What is the ruling if one joins the Imam for the final rak'ah of Witr?
Chapter on the Times When Prayer is Prohibited
Al-Mughni
Book of Prayer
Primary text
If the Imam separates the preceding two rak'ahs from the final Witr rak'ah with a Taslim (salutation), the single rak'ah joined suffices for the follower. If the Imam does not perform Taslim after the two preceding rak'ahs, the follower should follow the Imam, complete what the Imam performed, and upon finishing, stand to make up the missed portion without reciting the Qunut supplication in the subsequent makeup portion.