the correct view, if one deliberately omits congregational prayer, one’s prayer is not invalid, because praying in congregation is obligatory for the prayer, not obligatory within it.

His statement, “only”: qatt means “enough” or “sufficient.” An example is found in the hadith: “Hell will continue to have people cast into it while it says, ‘Are there any more?’ until the Lord of Might places His foot in it—or upon it, His leg—whereupon it will fold in upon itself and say, ‘Enough, enough...’” (1) That is, “I have had enough.”

Excluded by his statement, “only,” is that whose preferable time is after the salām. The prayer is not invalidated by omitting it, though one sins by omitting it where it is obligatory.

“And if he forgets it and says the salām, he should prostrate if only a short time has elapsed. ..........”

His statement, “And if he forgets it and says the salām, he should prostrate if only a short time has elapsed,” refers to the prostration that is to be performed before the salām. If he forgets it and says the salām, he should prostrate if only a short time has elapsed; but if a long time has passed, it lapses and his prayer remains valid.

For example, a man forgets the first tashahhud. He is therefore required to perform the prostration of forgetfulness, whose proper place is before the salām. However, he forgets and says the salām. If he remembers after a short time, he should prostrate; but if a long interval has passed, it lapses. Thus, if he does not remember until a considerable time has passed—hence the author’s statement, “he should prostrate if only a short time has elapsed”—then, if he has left the mosque, he does not return to the mosque, and it lapses for him. This differs from one who says the salām before completing the prayer: he must return and complete it, because in the latter case he has omitted an essential pillar, which he must perform; whereas here he has omitted an obligation that is waived when forgotten.