القيوم
كلمةُ (القَيُّوم) في اللغة صيغةُ مبالغة من القِيام، على وزنِ...
Abu Sa‘īd al-Khudri (may Allah be pleased with him) reported that the Messenger of Allah (may Allah's peace and blessings be upon him) said: "When anyone of you is in doubt about his prayer and he does not know how much he has prayed, three or four (Rak‘ahs), he should cast aside his doubt and base his prayer on what he is sure of, and then he should perform two prostrations before giving salutations. If he has prayed five Rak‘ahs, they will make his prayer an even number for him, and if he has prayed exactly four, then they will be a humiliation for the devil."
The Hadīth explains how a Muslim should address the doubts that he encounters while offering the prayer. In such a case, a Muslim should act upon the number of Rak‘ahs which he is certain of. If he has doubts about the number of Rak‘ahs, he is to count the less number of Rak‘ahs which he is certain of. He should complete the prayer as due and then offer two prostrations of forgetfulness before making the salutation. According to the Hadīth under study, the Prophet (may Allah's peace and blessings be upon him) said: "If anyone of you is doubtful about his prayer", meaning: if he is in a state of uncertainty and cannot verify the number of Rak‘ahs which he has actually prayed. For example, he is not sure whether he has performed three or four Rak‘ahs, so he should discard his doubts, namely, the fourth Rak‘ahs. Afterwards, he is to build on the number of Rak‘ahs which he is sure of, which is three. "Then he should offer two prostrations before he makes the salutation." This Prophetic statement proves that offering the prostration of forgetfulness before the salutation is better. "Thus, if he has offered five Rak‘ahs", here, he highlights the reason why the person is ordered to offer the prostration of forgetfulness. That is, assuming that he had actually offered four Rak‘ahs and then added one more, the total number of Rak‘ahs becomes five; then the two prostrations, which represent one Rak‘ah, makes the prayer even-numbered, as corresponding to the nature of the four-Rak‘ah prayer given as example in the Hadīth. If he already had performed four Rak‘ahs, then he had done what he is required to do, so the two prostrations, in this case, are intended for inflicting humiliation and disgrace upon the devil. And Allah knows best.