What is the ruling on someone who prays ten cycles (rak'ahs) of Tarawih and then wishes to pray Witr with the Imam out of laziness? Should he join him with the intention of Witr and then Salaam after the first cycle, or should he sit until the Imam finishes his Salaam, or should he wait until the first cycle is completed and then join him with the intention of Witr?

It is recommended to complete the prayer with the Imam to obtain the reward of spending an entire night in prayer, unless there is a valid excuse preventing it. It is permissible for theer to pray Witr with the Imam while he is praying Taraweeh, because a difference in intention between the Imam and the follower does not affect the validity of the prayer. If the worshiper wishes to pray Witr with the Imam during the shaf' (even-numbered rak'ahs), he has the option to join him and conclude his prayer with him after the tashahhud, or to wait for the Imam and conclude his prayer with him. The best approach is for the worshiper to complete these two rak'ahs with the Imam, then perform a third rak'ah to make it an odd-numbered (Witr) prayer for himself. However, if there is an Imam who prays eleven rak'ahs, it is preferable to pray with him to complete the reward and avoid contradicting the Imam.