The ruling on the prayer of one who has performed witr at home and then enters the mosque

The Shaykh : Yes, I am pleased to inform you that we have extended the time by a quarter of an hour.

The questioner : Poor things. As for the matter. Good. Welcome.

The Shaykh : Whoever wants it.

The questioner : Welcome. This is a brother who sent us this observation, which is that some of the brothers, when they enter the mosque and the imam is praying tarawih, do not join the imam on the grounds that they have already performed witr. What is your opinion, Honorable Shaykh?

The Shaykh : Yes. In the name of Allah, the Most Merciful, the Bestower of Mercy. The Messenger of Allah (peace and blessings be upon him) said: and he did not say, "If you have prayed witr, do not pray." There is a difference between the two expressions. So the person, when he finishes the night prayer...
But if there is a reason for prayer after this witr, there is no prohibition on praying. Yes, if the Messenger (peace and blessings be upon him) had said, "If you have performed witr, do not pray," we would say, do not pray after this, because you are prohibited. So if a person performs witr in his mosque and enters the mosque, whether there is a congregation or not, he should not sit until he prays two rak'ahs. And if there is a congregation, he is commanded to pray from two angles.
The first angle is for entering the mosque, and the second angle is for joining the congregation, based on the saying of the Messenger (peace and blessings be upon him) to the two men he saw who had not prayed the Fajr prayer with him. He said: So we say, O brothers, enter with us into the prayer.
And if you have already performed witr, there are not two witr in one night. So when the imam enters into witr, make your intention for an even number. When he concludes the prayer, add one rak'ah. This has a basis in the Sunnah. Its basis in the Sunnah is that when the Messenger of Allah (peace and blessings be upon him) was praying the four-rak'ah prayer with the people of Makkah and shortening it, he would say to them, "Complete it, O people of Makkah, for we are a traveling people." So when the Messenger (peace and blessings be upon him) concluded the shortened prayer, they stood up and completed it. This is not a contradiction of the imam. Contradicting the imam is to contradict him while you are bound to him, not to add to his prayer when the requirement of your prayer is to add, because you did not contradict him while you were bound to him.