What is meant by "depart" in the Hadith: "Whoever prays with the Imam until he departs, it will be recorded for him as if he had spent the entire night in prayer"? Does it mean performing the Witr prayer with the Imam, or his moving from the mihrab, or his leaving the mosque?

The meaning of the hadith "Whoever prays with the Imam until he departs, it will be recorded for him as if he prayed the entire night" is that the reward of praying a whole night is recorded for the worshiper if he prays the Tarawih prayer with the Imam until the prayer is finished, and the departure of the Imam does not mean his leaving the mosque or the mihrab.