What is the difference between forgetfulness in prayer and forgetfulness regarding prayer?

The questioner : The sixth question: What is the difference between forgetfulness regarding prayer and forgetfulness in prayer, which of the two is blameworthy, what is the evidence, and what is the rule for the prostration of forgetfulness after the closing salam, and what is the group?

The Shaykh : Well, the difference between forgetfulness regarding prayer and forgetfulness in prayer is that forgetfulness regarding it is negligence toward it and turning away from it, and this is the blameworthy one, due to the saying of Allah the Exalted: , which means the same as His saying: . As for forgetfulness in prayer, it is forgetting something of the prayer, whether from its obligations, its pillars, or something similar, and this is not blameworthy because it is part of human nature. This is why it happened to the master of humanity, Muhammad (peace and blessings be upon him); he forgot on several occasions, and . One day he prayed the midday or afternoon prayer with two rak'ahs and gave the salam. He prayed two rak'ahs and gave the salam, but he (may Allah's blessings and peace be upon him) gave the salam while looking downcast. He stood up and leaned on a wooden post in the front of the mosque, interlaced his fingers like this, and placed his cheek on the back of his hand. If you see a man doing this, it means he is worried.
Therefore, it was said that he looked angry. The wisdom behind this is that it was an emotional reaction, as he had exited the worship before completing it. The Muslims feared the Messenger (peace and blessings be upon him) because Allah placed awe in his noble person. Whoever saw him would fear him with great awe, but when a person mixed with him, he found him the easiest of people and the greatest in cheerfulness (may Allah's blessings and peace be upon him). Among those present were Abu Bakr and 'Umar, and yet they feared to speak to him; they refused to honor him by saying, "You gave the salam before the completion."
And among the people was a man with long hands. The Prophet (peace and blessings be upon him) used to joke with him and call him, saying, "O you of the long hands," because of the length of his hands. It is known that if a person jokes with someone, that person becomes bolder with him than with others, but this man was well-mannered and logical. If the logicians had wanted to come up with an example of his phrasing, they would have spent days formulating it.
So he said, "O Messenger of Allah, did you forget or did you shorten the prayer?" He mentioned what? Two possibilities: either forgetting or shortening the prayer. And a third possibility remained: what is it? That he intentionally gave the salam before the completion. This is not applicable, and therefore it did not occur, because it is impossible. The impossibility is that the Messenger (peace and blessings be upon him) would intentionally give the salam before completing the prayer. So he mentioned the two possibilities: "Did you forget?" Is this possible or not? It is possible. "Or did you shorten the prayer?" Is it possible that the completion was abrogated to shortening, just as shortening was abrogated to completion for the prayer of residents, and the prayer of travelers was confirmed? How did the Chosen One (peace and blessings be upon him) answer him? He said, "I did not forget and the prayer was not shortened." Glory be to Allah, the Messenger says, "I did not forget and the prayer was not shortened," denying the forgetting and denying the intention, even though one of them must have occurred.
So the man said to him, "No, you did forget." And he left the phrase "did you shorten the prayer" out. Why? Because the possibility that he shortened it is very remote. But the possibility of forgetting is closer. Therefore, he said, "No, you did forget." So they gathered with the Messenger (peace and blessings be upon him).