with a second takbīr, for this is the preferable course. If he confines himself to the opening takbīr alone, it will suffice for the bowing takbīr as well. The takbīrat al-iḥrām must be pronounced while standing, whereas it is merely recommended to follow it with the takbīr for rukūʿ.
If the latecomer finds the imam in any posture of the prayer, he should join him immediately. Abū Hurayrah and others relate that the Prophet ﷺ said, “When you come to the prayer while we are in prostration, then prostrate, and do not count it as anything.”
When the imam completes the second salām, the latecomer rises to perform the portions of the prayer he has missed; he must not rise before the second salām.
According to the sounder opinion, whatever the latecomer performs with the imam counts as the beginning of his own prayer, and what he performs after the imam’s salām is its end. The Prophet ﷺ said, “Whatever you catch up with, complete it,” the wording reported by the majority. Completion can only follow what precedes it. The alternative wording, “Whatever you miss, make up,” does not contradict “complete,” for the term qaḍāʾ here simply means “to perform.”1 Allah, exalted is He, knows best.
1 See, for example, the verses: “When the prayer is concluded…” (Q 4:103) and “When you have completed your pilgrimage rites…” (Q 2:200), where qaḍāʾ denotes completion or performance.