delay the intention beyond that, it is sufficient for him. If he combines during the time of the second prayer, the time for the intention is during the time of the first prayer, from its beginning until there remains enough time to perform it; for if he delays it beyond that without intention, it becomes qada' (making up a missed prayer) rather than jam' (combining). It is possible that the time for the intention extends until there remains enough time to catch it, which is one rak'ah or the opening takbir, based on what we previously mentioned. What our companions have mentioned is the former, for delaying it beyond the amount required to perform it is haram (forbidden).

Section: If he combines during the time of the first prayer, sequence (muwasala) between them is considered, which is that he does not separate them except by a slight interval. If he prolongs the separation between them, it becomes void, because the meaning of combining is sequence or proximity, and since sequence is not possible, only proximity remains. If he separates them by a long interval, the combining is void, regardless of whether he separated them due to sleep, forgetfulness, preoccupation, intention, or otherwise, because the condition cannot be established without the restricted act. If the interval is slight, it does not prevent it, as it is impossible to avoid, and the reference for what constitutes 'slight' or 'long' is custom and habit; it has no limit other than that. Some of our companions estimated it by the length of the iqamah and wudu, but the correct view is that it has no set limit, because that for which the Shari'a has not provided a measure cannot be measured, and the reference is to custom, like guarding or taking possession. Whenever he needs to perform wudu or tayammum, he should do so as long as the separation is not prolonged. If he speaks a little bit, the combination is not void. If he prays the Sunnah between them, the combination is void, because he separated them with a prayer; thus, the combination is void, just as if he had prayed [another prayer] between them.