What is the ruling on specifically saying "May Allah accept it" after finishing the prayer?

The questioner : There is a man who, when he prays in the mosque and then leaves, the worshippers say to him, "May Allah accept it." Naturally, he has heard from us that it is better for them to say, "Peace be upon you," so he tells them, "Say, 'Peace be upon you.'" They asked their Shaykh about that, and he told them, "Do not say 'May Allah accept it' to him, and Allah will not accept it from him. Do not respond to him." This is a Wahhabi, so he wants to hear from you a detailed explanation of the matter, meaning that what is transmitted in the Sunnah is "Peace be upon you," not "May Allah accept it."

The Shaykh : What we believe is that the best guidance is the guidance of Muhammad (peace and blessings be upon him), and we are certain of this and call people to it.
However, this belief does not benefit its holder unless it is accompanied by knowledge of the guidance of the Messenger (peace be upon him) in everything related to the religion. This includes prayer. The Messenger of Allah (peace and blessings be upon him and his family) prayed thousands of prayers with the Companions (may Allah be pleased with them), yet it was not reported that he said to any of them after the prayer, "May Allah accept it," or that any of them said to him, "May Allah accept it," and he in turn said, "From us and from you," or something like that, "May Allah accept good deeds." None of this was reported from the Prophet (peace and blessings be upon him), not a single word.
In addition to that, we know the importance of spreading peace in Islam to the extent that it was made a prerequisite for entering Paradise. He (peace and blessings be upon him) said, "By Him in whose hand is my soul, you will not enter Paradise until you believe, and you will not believe until you love one another. Shall I inform you of something that, if you do it, you will love one another? Spread peace among yourselves." This spreading does not mean merely throwing it out; rather, spreading it is throwing it out and adding to it, which is increasing this throwing out. This increase, which is the Muslim’s frequenting of greeting his Muslim brother and his Muslim brothers with peace, is the spreading for which the Messenger (peace be upon him) established that sound logical sequence leading to Paradise and bliss. The Messenger (peace be upon him) explained in some of his hadiths examples of this type of spreading of peace. He used to greet, contrary to what many jurists think. He used to greet the congregation while they were reciting the Qur'an, and people say, "One does not greet the reciter of the Qur'an." Also, among the spreading of peace is that his Companions used to greet him before his migration to Abyssinia and after it. But the greeting before the migration was returned by the one being greeted and the one praying verbally. A man would come to his companion and catch up with the prayer, and he would say, "Peace be upon you and the mercy of Allah," and he would respond while in prayer, "And upon you peace and the mercy of Allah." This was how they were in the early days of Islam, before the migration to Abyssinia. Then the returning of the greeting by the praying person to the one who greeted him was abrogated. The verbal return was abrogated, and what remained before the verbal return was the gesture with the head or the hand. It came in Sunan Abu Dawud from the hadith of Ibn Mas'ud that when he returned from Abyssinia and came to the Prophet (peace and blessings be upon him) and found him praying, he said, "Peace be upon you, O Messenger of Allah." He was waiting for him to return the greeting verbally, as was the case before he migrated to Abyssinia. But he was surprised by something new, where he found that the Messenger (peace be upon him) did not return his greeting with a greeting. He said, "I was seized by what was near and what was far," meaning his mind was turning over from near and far: what did I do? What did I do until I was deprived of the return of the greeting from my Prophet to me? He began to think. Then he greeted when he finished his prayer and said to Ibn Mas'ud, "Indeed, Allah brings about in His affairs what He wills, and among what He has brought about is that there is no speech in prayer." "Peace be upon you" and "And upon you peace" — this is the address and the response. This was abrogated.
But if the original practice, which was returning the greeting verbally, has been abrogated, the Wise Lawgiver has established in place of the words a symbol and a gesture, which is the response like this or like this. Therefore, in some narrations of this hadith of Mas'ud, it is mentioned that he gestured to him with his head and excused himself to him by saying, "Indeed, Allah brings about in His affairs what He wills, and among what He has brought about is that there is no speech in prayer." Also, in Sunan Abu Dawud, there is the hadith of 'Abdullah ibn 'Umar ibn al-Khattab that the Prophet (peace and blessings be upon him) visited the Ansar in their mosque in Quba, and whenever they entered upon him, they would greet him while he was praying, so he would return the greeting to them with a gesture of his hand. One of its narrators described this gesture, saying, "He would place the palm of his hand toward the ground and the back of his hand toward the sky." "Peace be upon you and the mercy of Allah" — "Peace be upon you and the mercy of Allah," and so on.
Once we know this fact, which is the importance Islam places on spreading peace, we know that you, O Muslim, when you enter the mosque, you must greet, and when you meet your Muslim brother, whether in entering or exiting, the greeting is necessary, due to his saying (peace and blessings be upon him), "The right of a Muslim over a Muslim is five: when you meet him, greet him." Today, when Muslims have turned away from studying the Book of Allah and the hadith of the Messenger of Allah (peace and blessings be upon him), a wide door of ignorance has opened before them, and thousands upon thousands of innovations have entered through it, and they approve of them due to their ignorance of the Sunnah. Otherwise, how can I be a Muslim who truly believes that the best guidance is the guidance of Muhammad, and he prayed thousands of prayers, and not once did he say to any of the Companions, "May Allah accept it"? We say, "No, this is a gift," and those who deny that it is a gift are misguided Wahhabis. On the other hand, they lose what the Messenger taught the Ummah regarding the spreading of peace: "When you meet him, greet him." And we observe that this is abrogated with them. Meaning, he enters the mosque and catches up with the Imam in prayer, so I pray, and then I leave, and my companion whom I had not met before meets me and says, "May Allah accept it." He told you, "When you meet him, greet him." You do not greet him. No one teaches them or sees that people... some of them say to each other, "May Allah accept it," and people follow people as if the Lord of the Worlds said so to them in the Qur'an. He did not say to them He did not say, "Follow the people, O people."
Therefore, we truly believe what came from some of the Salaf: "No innovation was introduced except that a Sunnah was killed." This is like... in... the Fire. We never see it, but the others do not see it because they are not interested in the issue. One of them enters the mosque and finds his companion in the ablution area performing wudu, and he tells him, "From Zamzam?" And where is the peace? It has flown away — and he is saying, "When you meet him, greet him." He met him, but you do not greet him? From Zamzam, it has taken its place. "No innovation was introduced except that a Sunnah was killed." It is of this kind. We have finished the prayer, and you meet your companion, and you say to him, "Peace be upon you." This is first, implementing the command: "When you meet him, greet him." You met him, so greet him. Second, it is spreading peace. If you and he entered the mosque together, and you went to perform wudu, and he went to pray the Sunnah, and then you finished the prayer and you are leaving, you meet, "Peace be upon you." This is from spreading peace. The Companions of the Messenger (peace be upon him) knew the importance of spreading to the extent that we now consider it a burden. If we apply this spreading, we find it a burden. If they were with the Messenger on a journey, and they were in the desert, and a tree or a rock separated them, and they met after it, "Peace be upon you," "Peace be upon you." Were they absent from each other? No, but it is "Spread peace among yourselves." What does "Peace be upon you, O people" mean? It means "The name of Allah is upon you," as he (peace be upon him) said. Peace is one of the names of Allah, which He placed on earth, so spread it among yourselves. So "Peace be upon you" means "The name of Allah is upon you," meaning you are under the care, protection, and shelter of Allah, and so on. They abolished this spreading of peace. Like this, when they met from behind a tree or a stone, some of them would say to others, "Peace be upon you." Ibn 'Umar ibn al-Khattab used to say to his slave Nafi', "Let us go to the market." O Allah, enter the market. Nafi' would say, and I know that he has no need in the market, but he wants to throw the greeting to those he meets from the Muslims.
The student : He said to him once, "What do we do in the market? You do not buy and you do not sell." He said, "I spread peace to the people..."

The Shaykh : So look at how the Muslims today have changed the Shari'ah with their ignorance. "May Allah accept it" — this, O brothers, is an innovation, and the greeting is obligatory to throw and return, and spreading it is also obligatory, and it may be obligatory, and it is undoubtedly a recommended practice. Therefore, strive for the Sunnahs so that the innovations die, and beware of the innovations, for they are the amulets of the Sunnahs. And in this is a reminder, and the reminder benefits the believers, if Allah wills. And this amount is sufficient for you, for the time has passed eleven o'clock.