What is the origin of the abbreviated form of sending blessings upon the Prophet (peace and blessings be upon him) found in the books of hadith and common on the tongues of people, which is "sallallahu alayhi wa sallam"?

The questioner : A questioner asks: What is the origin of the abbreviated form of sending blessings upon the Prophet (peace and blessings be upon him) found in the books of hadith and common on the tongues of people, which is their saying "sallallahu alayhi wa sallam", even though the Prophet (peace and blessings be upon him) taught them how to send blessings upon him generally in prayer and otherwise. He taught them how to send blessings upon him generally in prayer and otherwise. They said: O Messenger of Allah, we have learned how to greet you, so how do we send blessings upon you? He said: Say "O Allah, send blessings upon Muhammad and upon the family of Muhammad, as You sent blessings upon Ibrahim and upon the family of Ibrahim. O Allah, send peace upon Muhammad and upon the family of Muhammad, as You sent peace upon Ibrahim and upon the family of Ibrahim. Indeed, You are Praiseworthy and Majestic"?

The Shaykh : In my opinion, this is an important question, and the answer to it clarifies a reality that many people have long overlooked, including some of the specialists. This is the reality we always and forever say: that a Muslim must not be content with his call being limited to merely adhering to the Book and the Sunnah, but he must add to that the methodology of the righteous Salaf: the Book and the Sunnah according to the methodology of the righteous Salaf. The reason that compels us to say that adhering to this addition or this adjunct, "according to the methodology of the righteous Salaf," is necessary, is matters from revelation and reason. As for revelation, you know the saying of Allah the Exalted: So our Lord the Exalted did not say in vain, but for a profound wisdom. Because if He had said, "And whoever opposes the Messenger after the clear proof has come to him, We will turn him to what he has turned to," etc., there would have been room for every misguided person who deviates from the Book and the Sunnah in the correct sense, who has departed from the community in the manner in which the Messenger of Allah (peace and blessings be upon him) departed from it, to say: This is what I understood from the verse and the hadith. But so that this understanding would not be chaos without a rule or a criterion, Allah the Exalted said: to make it clear to people that it is not sufficient, and it is not permissible, for every Muslim to understand the Book and the Sunnah as it appears to him, but he must understand them as our righteous Salaf understood them. Therefore, the intended meaning here of the believers here is our righteous Salaf, whom the Messenger (peace be upon him) testified to with that testimony by which they were distinguished from those who came after them, in the authentic, indeed mass-transmitted hadith: This is from the perspective of this noble verse. Then the Sunnah comes, as is its constant and eternal habit, with the Qur'an to explain and clarify. The Messenger (peace be upon him) said in the well-known hadith of the seventy-three sects, when he was asked about his saying: Who are they? And similarly, the hadith of al-'Arba' ibn Sari'ah, which begins: "The Messenger of Allah (peace and blessings be upon him) gave us a sermon that made our hearts tremble and our eyes shed tears," to the end of the hadith. He (peace be upon him) said: to the end of the hadith. So this hadith and that one make it clear to us that we cannot do without the understanding of what our righteous Salaf were upon, especially the Companions (may Allah be pleased with them), because they were closer to him (peace and blessings be upon him) than we are in understanding, knowledge, observation, sight, application, and everything of this kind. Therefore, just as we receive the words of the Shari'ah, the Qur'an and the hadith, from these Salaf, we must also receive the meanings of these texts from the Book and the Sunnah. It is not enough for one of us today, after fourteen centuries, to say: "By Allah, this is my understanding," especially in rulings, and more specifically in matters of creed, where the practice has been established, whether it is a heart-based, faith-based practice or a physical, limb-based practice. There is no doubt that they understood these matters correctly. So whoever comes after them with an opinion that contradicts what they were upon in creed or in legal rulings, there is no doubt that he is contrary to the way of the believers, and thus he falls under the general meaning of the aforementioned saying of Allah the Exalted: Once this important principle is known, the beginning of the answer to this question becomes clear.
We know with certainty that the Companions who transmitted his (peace be upon him) hadiths to us, then the Tabi'un, then their followers, and as we mentioned, the generations testified to as being the best, when they narrated a hadith from the hadiths of the Messenger of Allah (peace and blessings be upon him) and began it by saying, "The Messenger of Allah (peace and blessings be upon him) said," or one of them said, "The Messenger of Allah used to do such and such" or "say such and such," we know with certainty that none of them would say, "The Messenger of Allah said: O Allah, send blessings upon him, O Allah, send blessings upon Muhammad and upon the family of Muhammad," or "May Allah send blessings upon Muhammad and upon the family of Muhammad, as You sent blessings..." to the end of the Ibrahimi blessing. We are certain that they did not say it this way. Therefore, we do not say that the place of applying the Qur'anic text mentioned in the question, and that its generality requires that the blessing be in the form that the Messenger of Allah (peace and blessings be upon him) taught his Companions, is the case. There is a prior discussion that a general text that has not been acted upon is not permissible for us to act upon a part of its parts that has not been acted upon. Rather, what we know was applied, we apply, and what we know was left from its parts, we leave. And this is following: that we do what they did and leave what they left.
So here a question may arise: What do we say? We say: As it is in the books of hadith, those of the early hadith masters who were concerned with precision in narrating hadiths, even down to a single letter, we do not imagine either of two things. We do not imagine that a Companion would say, "The Messenger of Allah said: The Messenger of Allah used to do such and such," meaning he did not send blessings upon him. This is the first thing we do not imagine. The second thing we do not imagine is that he would say, "The Messenger of Allah (peace and blessings be upon him)..." "The Messenger of Allah (peace and blessings be upon him)..." excuse me, the habit overtook him, "The Messenger of Allah," and he would stop here and say: "O Allah, send blessings upon Muhammad..." We also do not imagine that this occurred. Why? And this is connected to the recent discussion from yesterday, because if it had occurred, it would have been transmitted to us, because the motivations for transmitting this important matter would be present whenever the Companion mentioned the Messenger of Allah (peace and blessings be upon him) in a hadith of his, from his (peace and blessings be upon him) saying... he would stop and send blessings upon him as they were taught. If this had occurred, even once, the motivations for transmitting it would have been present. How could it be otherwise when they multiplied the hadiths by the hundreds, indeed by the thousands upon thousands, and it was not found in a single hadith that one of them sent blessings upon the Prophet (peace and blessings be upon him) with this complete, full blessing.
From here, I arrive at the conclusion that this general Qur'anic text is not intended in its generality, but rather this is specific to prayer. This is supported by a narration reported by al-Hakim, and perhaps by Imam Ahmad in the Musnad, that when this verse was revealed, they said: O Messenger of Allah, we have known this greeting to you. This is found in the authentic collections, but the continuation is the point of interest: "We have known this greeting to you, so how do we send blessings upon you when we sit in our prayer?" He said: Say So this blessing is in its place in prayer, and not outside of prayer. And with this, the answer to the question ends.

The questioner : May Allah bless you.

The Shaykh : And among you.