Regarding the greeting of peace, which is one of the rites of Islam.

The Shaykh : ... and among the worst of our deeds, whoever Allah guides has no one to mislead, and whoever He misleads has no one to guide. And I bear witness that there is no god but Allah alone, with no partner, and I bear witness that Muhammad is His slave and His Messenger, , , . As for what follows:
Indeed, the best of speech is the speech of Allah, and the best of guidance is the guidance of Muhammad (peace and blessings be upon him), and the worst of matters are their innovations, and every innovation is a religious innovation, and every religious innovation is misguidance, and every misguidance is in the Fire. And after that:
It has been placed in my heart that I should address you with a word that I hope will be brief and concise regarding the greeting of peace, which is one of the rites of Islam. This name, "peace," as he (peace and blessings be upon him) said in the hadith that Imam al-Bukhari narrated in his book *Al-Adab al-Mufrad* with his authentic chain from Abu Hurayrah, from the Prophet (peace and blessings be upon him and his family), who said: . And it came in another hadith that Imam Muslim narrated in his *Sahih* from the hadith of Abu Hurayrah—also—who said: The Messenger of Allah (peace and blessings be upon him) said: .
His saying (peace and blessings be upon him) at the end of this hadith: means increasing the offering of the greeting of peace by a Muslim to his Muslim brother. And it is not only when meeting him; for it is among the obligations that are the right of a Muslim upon a Muslim, as came in another hadith: . That I should circle around this topic somewhat is because it is a greeting that many people have neglected today. It is of two forms: one relates to sending blessings upon the one who is praying, and the other relates to the greeting when leaving the gathering.
As for the first issue—which is offering the greeting of peace to the one standing in prayer or to those standing in prayer—this is a recommended practice (sunnah) that has been abandoned in both knowledge and practice. Therefore, I wanted to remind you of it, for the reminder benefits the believers. Among the spreading of the greeting of peace is what is established from the Prophet (peace and blessings be upon him and his family) that he visited the Ansar in their mosque—Masjid Quba—on a certain day. So whenever a group entered to greet the Prophet (peace and blessings be upon him and his family) while he was standing in prayer, and they offered the greeting to him, he returned the greeting to them with a gesture of his hand. The narrator of the hadith—and he is Ja'far ibn Dhirgham—said: We said, How did he return the greeting while he was praying? He answered that the Prophet (peace and blessings be upon him and his family) would make his palm face the ground and the back of his hand face the sky. Whenever a Muslim who greeted him entered, he would say, "Like this, like this." This movement is the return of the greeting of the one who greeted him verbally by the one occupied with prayer. And because the one praying is occupied with what he is in, namely the recitation or the glorification appropriate for each pillar, he was unable to return the greeting verbally. Even though that was prescribed at the beginning, in the early days of Islam, it came from Ibn Mas'ud (may Allah be pleased with him) that when he returned from his migration to Abyssinia, and the first thing he encountered with the Prophet (peace and blessings be upon him and his family) in Medina was finding him praying, he offered the greeting to him verbally as is obligatory. But he (may Allah be pleased with him) was surprised by what he had not expected; that is, the Prophet (peace and blessings be upon him and his family) did not return the greeting to him verbally, but rather gestured to him with his head like this. Abdullah ibn Mas'ud said: I was seized by what was near and what was far; I was questioning myself, wondering, saying, What have I committed? What have I done that the Prophet (peace and blessings be upon him and his family) did not return the greeting to me? So when the Messenger of Allah (peace and blessings be upon him and his family) finished the prayer, he said: .
So this speech between the one offering the greeting to the one praying and the return of the greeting by the one praying was verbal. Thus, Abdullah ibn Mas'ud parted from his Prophet (peace and blessings be upon him and his family) when he migrated to Abyssinia. Therefore, the surprise of what he saw from the Prophet (peace and blessings be upon him and his family) for the first time after he had parted from him was that his understanding was that the Prophet (peace and blessings be upon him and his family) returns the greeting in prayer verbally. That is because speech was among the rulings that were not immediately forbidden in prayer; that is, it was not among the forbidden things in prayer when they were commanded to pray. Rather, speech was forbidden afterwards. So much so that the one praying would enter the mosque and find the prayer established, and not know whether this rak'ah is the first or the second. He would stand in the row and ask the one standing in prayer: Which rak'ah is this? This was before the prohibition in prayer. He would answer him, "This is the first rak'ah," or "It is the second rak'ah." If he had missed a rak'ah, what would this one who missed a rak'ah do? He would come with the missed rak'ah, then join the imam in his prayer. This was the case at the beginning, before the prohibition of speech in prayer, until one day Mu'adh ibn Jabal (may Allah be pleased with him) entered and did not do as they used to do. He did not ask the one on his side, but rather entered the state of ihram and followed the Prophet (peace and blessings be upon him and his family). Then when the prayer was completed, he stood up and made up the missed rak'ah. So he (peace and blessings be upon him) said: , meaning: There is no longer a need for the one who joined late to make up the missed rak'ah as they used to do before, after asking the praying people, but rather he should do as Mu'adh (may Allah be pleased with him) did. And this is what he (peace and blessings be upon him) affirmed in the hadith agreed upon byThe Shaykh : al-Bukhari and Muslim; where they narrated from the Prophet (peace and blessings be upon him and his family): ; meaning: As Mu'adh (may Allah be pleased with him) did. And Allah (Mighty and Majestic) abrogated the previous ruling, which was the conversation of a man with his brother in prayer, so Allah revealed His saying (Blessed and Exalted is He): ; meaning: Silent, with no speech in prayer.
It appears that some of the Companions who did not grasp this new ruling—that is, preventing the one praying from speaking in prayer—remained with their old knowledge that we mentioned earlier, with which Ibn Mas'ud parted from the Messenger (peace and blessings be upon him and his family). And therefore, when he offered the greeting to him, he hoped to hear the return of the greeting from his mouth (peace and blessings be upon him and his family). And you know the rest of the hadith. It appears that one of the Companions did not grasp this new ruling, which is that there is no speech in prayer; I mean by that the Companion Mu'awiyah ibn al-Hakam al-Sulami (may Allah be pleased with him). And this Mu'awiyah is not Mu'awiyah ibn Abi Sufyan al-Umawi, the caliph after the Rightly Guided Caliphs, as you know. Mu'awiyah ibn al-Hakam al-Sulami narrated about himself and said: I prayed one day behind the Prophet (peace and blessings be upon him and his family), so a man next to me sneezed, and I said to him: May Allah have mercy on you (this is according to the original text). So they looked at him with the corners of their eyes, silencing him. But the man was annoyed by these looks directed at him, so he said: Woe to my mother! What is wrong with you that you are looking at me? (He thought he had done nothing; he had congratulated his companion: May Allah have mercy on you!). Mu'awiyah said: So they struck their thighs, saying to him, Be quiet. He said: When the Messenger of Allah (peace and blessings be upon him and his family) finished the prayer, he turned to me; and by Allah, he did not humiliate me, nor did he rebuke me, nor did he strike me, nor did he curse me, but rather he said to me: , meaning: The speech that was previously permissible, . Thus, the Prophet (peace and blessings be upon him and his family) disciplined this man, the Companion Mu'awiyah ibn al-Hakam al-Sulami, who had not grasped the new ruling; that is, what is narrated in the Qur'an, in addition to the Sunnah: ; meaning: Silent, with no conversation.
Perhaps the greatest benefit of completing this discussion is to mention the full text of this hadith; for in Mu'awiyah’s turning to the Prophet (peace and blessings be upon him) with a series of questions, there is a demonstration of the effect of good upbringing and the use of gentleness and kindness with one who is ignorant of some of the rulings of the religion. You have heard previously in this hadith that the man, after realizing he had made a grave error in his prayer—judging by the Companions’ looks at him and their striking their thighs—understood from all of this that he had made a serious mistake. When he saw the Messenger of Allah (peace and blessings be upon him) approaching him, he imagined that he would be rebuked, cursed, or struck. But the natural result for one to whom Allah (Blessed and Exalted is He) said in His Book: is to see something other than what he may have imagined in his mind. And so he said: When the Messenger of Allah (peace and blessings be upon him) approached me, "By Allah, He did not humiliate me, nor dominate me, nor strike me, nor curse me, but only said to me: ." When he found this noble Prophetic gentleness, he began to direct question after question to the Prophet (peace and blessings be upon him) to make up for what he might need to know regarding the ruling of Allah (Mighty and Majestic) in those matters. Among what he said to the Prophet (peace and blessings be upon him) was: "O Messenger of Allah, some of us visit fortune-tellers." He said: . He said: "Some of us take omens." He said: . He said: "Some of us draw lines in the sand"—meaning they practice divination by casting sand. He (peace and blessings be upon him) said: . He said: "O Messenger of Allah—and this was his last question—I have a slave girl who tends my sheep in al-Hudaybiyah. One day a wolf attacked my sheep, and I am a human being who gets angry as humans do; so I struck her a blow, and I am obligated to free a slave."—He means: I want to fulfill this vow upon me, which is freeing a slave, and I have a slave girl; will it benefit me if I free her?—He (peace and blessings be upon him) said: . He brought her, and the Prophet (peace and blessings be upon him) said to the slave girl: . She said: "In the sky." He (peace and blessings be upon him) said: . She said: "The Messenger of Allah." He turned to her master and said to him: .
The aim of this discussion is not, in reality, to explain this great hadith and comment on every part of it. Rather, I mentioned it to show how the ruling developed and how it reached the prohibition of speech, including replying to the greeting with words, whereas previously, at the beginning, it was permissible and prescribed. I do not wish to explain this hadith in order to return to the hadith of Ibn Mas'ud; for when he greeted the Prophet (peace and blessings be upon him) and did not hear a verbal reply to the greeting, he said: "What was near and what was far took hold of me"—meaning he was thinking deeply about what he had committed and in what he had contradicted the Shari'ah, such that the Messenger of Allah (peace and blessings be upon him) did not return his greeting. Then the answer came to him after the Prophet (peace and blessings be upon him) had finished his prayer: . That is, in his religion, as he (peace and blessings be upon him) said in another hadith: . He (peace and blessings be upon him) said in the hadith of Ibn Mas'ud: . It is as if he were excusing Ibn Mas'ud, who was troubled by what was near and what was far, saying: Do not be concerned, for a new ruling has been revealed that there is no speech in prayer, and therefore I did not return your greeting but was content with a gesture. This gesture—and here is the crux of this speech—is the symbol and substitute for returning the greeting verbally, which was previously prescribed.
So, if someone greets a person who is praying, he has one of two states, or one of two gestures, by which the greeting is returned. If he is in a crowded place, like this blessed mosque which was full of worshippers, and the one entering says "As-salamu alaykum" without raising his voice much, but only greets those around him, then they should gesture with their hand. This gesture differs depending on whether the one entering is from behind the rows; in that case, the hand should be raised so that it is seen, and the worshipper should not be confused as Ibn Mas'ud was, wondering: Why did they not return my greeting? So at least some of them should raise their hands, because returning the greeting is a collective obligation; if some of them fulfill it, it is lifted from the rest. And if the one greeting is coming from the direction of the qiblah, such that the worshippers see him and he sees them, then it is sufficient for the one returning the greeting to raise his hand like this, without exaggerating in the raising, in order to fulfill the return of the greeting which is a substitute for the words, namely: "Wa alaykum as-salam." He has the choice between returning the greeting with a gesture of his hand or a gesture of his head. This complete gesture is only done if the group is small, or if the worshipper is alone, in which case the return of this greeting is shown by this gracious and easy gesture. This is the first type I wanted to draw attention to, regarding how the worshipper returns the greeting to the one who greeted him. And before moving on to the second type, it is necessary to remind you here that offering the greeting, as we said in the previously mentioned hadith: . So, the one who enters the prayer place or the mosque and meets his Muslim brother or brothers who are praying must hasten to greet them because he has met them, but the return of the greeting is only by gesture, as we mentioned.
As for the second type that I should point out—and this is also a neglected Sunnah, unfortunately—it is that offering the greeting upon meeting, and praise be to Allah, is still preserved in many Islamic countries, although some have begun to neglect this offering. One of them meets his brother, greets him with "Good morning" or "Good evening," and does not hasten to say to him: "As-salamu alaykum." And in some countries, if you offer the greeting, they do not return the greeting, but rather say to you: "Welcome" or "Glad to see you." And this is a sin beyond sin; for Allah (Mighty and Majestic) says in the well-known verse: . It is not hidden from any Muslim that the Islamic, Shari'ah greeting, as we said at the beginning of the hadith we mentioned just now, is: . So, if one offers this greeting to his Muslim brother, and then he hastens to say to him: "Welcome," "Glad to see you," "Good morning," "Good evening," returning his greeting not with what is better, nor with what is...; then this is a disobedience, and those Muslims must be mindful of it.
But the thing I want to remind you of now is that many of those who are keen to offer the greeting upon meeting do not care about offering the greeting upon parting. And here is the distinction: those who care about offering the greeting upon meeting do not care, and do not pay attention or heed, to offering the greeting upon separation. And the Messenger (peace and blessings be upon him) used to say: . This is what I wanted to remind you of; for I have found in most of the countries I have traveled to and entered that they neglect offering the greeting upon parting. Indeed, it may be that two people are walking together, and then one of them turns away, and his companion does not notice that he has turned away, because he did not say "As-salamu alaykum" upon parting; whereas the Prophet (peace and blessings be upon him) clarified in the last hadith that the greeting upon parting is like the greeting upon meeting, and that this greeting upon meeting is not more deserving than the greeting upon parting, . This is a reminder, and the reminder benefits the believers.
What do you have?