Is it prescribed for one who enters the mosque while people are praying to greet them?

The questioner : A questioner asks and says: If a Muslim enters the mosque while they are praying, does he greet them? If the people in the mosque are praying?

The Shaykh: Yes.

The questioner : Is it recommended for him—here—or is it mustahabb (recommended) for him to greet them?

The Shaykh : It has come in more than one hadith that the Companions, when they entered upon the Prophet (peace and blessings be upon him), would greet him. I will suffice now with mentioning one hadith for brevity, namely the hadith of 'Abdullah ibn 'Umar ibn al-Khattab (may Allah be pleased with him), who said: The Prophet (peace and blessings be upon him and his family) visited the Mosque of Quba, and the news of his arrival reached the Ansar, so they came to him while he was praying. So whenever a group of them entered, they said: "Peace be upon you, O Messenger of Allah," while he was praying. So he (peace and blessings be upon him) would return the greeting to them with a gesture of his hand. And one of the narrators of the hadith, whose name is Ja'far ibn 'Unayn, said: He raised his hand, placing the palm of it toward the ground and the back of it toward the sky, whenever some of the Ansar greeted him, saying "Peace be upon you, O Messenger of Allah." The Messenger (peace be upon him) would do this: "Peace be upon you, O Messenger of Allah," and the Messenger (peace be upon him) would do this. So when a man enters the mosque and the people are in prayer, the sunnah (recommended practice) is to spread the greeting, contrary to what many people think. Spreading the greeting does not mean merely throwing out the greeting; rather, the meaning of spreading the greeting is to increase the throwing out of the greeting. What does "the matter spread" mean? It means it spread by abundance. So when the Messenger (peace be upon him) said: , and he also said in another hadith: , so spreading the greeting is a broader meaning than merely throwing out the greeting. Spreading the greeting means that you use it on the slightest occasion. For example—I am compelled to lengthen the speech a bit here because I know that people are heedless of these Prophetic hadiths—for example: a man is sitting as a guest in one of their rooms, he asks permission to go out for some need, he goes out, and then returns, and it is as if he neither went out nor came in. Why? Because just as he went out without a greeting, he came in without a greeting. This is contrary to this Prophetic command: , and indeed it is contrary to an explicit hadith in this regard, namely his saying (peace and blessings be upon him and his family): . So you greet upon entering and exiting, meaning—as they say among us in the Levant—"like a saw, going up and down." You are written reward for it, because the Muslim's saying "Peace be upon you" is ten good deeds, as came in the authentic hadith. And if he says "Peace be upon you and Allah's mercy," it is twenty good deeds. And if he says "Peace be upon you and Allah's mercy and His blessings," it is thirty good deeds. So thirty and thirty is sixty in five minutes. What is recorded for you because of this? Your use of this word. This is part of the Messenger's (peace be upon him) detailing, the Messenger's detailing with his words of his previous word: .
And finally: I mention to you what is more amazing than that. Two men are walking in the road, and a stone or a tree separates them. So the Salaf, the Companions, when a stone or a tree separated them, one of them would hasten to greet the other, saying "Peace be upon you." We do this today, and people are surprised: who are you greeting? We were walking together, who are you greeting? I say to him: I am greeting you. What happened? I say: a stone or a tree separated us. This is part of the realization of his saying (peace be upon him): .
Finally: Among the things included in spreading the greeting is that you enter a man's house, or his mosque while he is praying, and you say: "Peace be upon you." This is spreading the greeting. But the one who is praying, as he is occupied with his prayer, with remembrance and recitation, is not able to return the greeting to you verbally, but rather with a gesture of his hand, and sometimes with a gesture of his head, and each has its place. And in any case, this has another discussion, and what we have mentioned is sufficient—if Allah wills.

The questioner : What if he is in bowing?