The ruling on one who catches a rak'ah of 'Isha' after it has been prayed in congregation

The questioner : The questioner says: Honorable Shaykh, I attended this mosque and caught the last rak'ah of the 'Isha' prayer. Should I complete the 'Isha' prayer, or should I just perform a second rak'ah? Please note that I had already prayed 'Isha' in congregation before I came to this mosque?

The Shaykh : The best course, without a doubt, is to complete the four rak'ahs, due to the generality of the saying of the Messenger (peace and blessings be upon him) . Also, because he saw two men when he prayed Fajr in the Musjid al-Khaif in Mina during the Farewell Pilgrimage. He saw two men who had not prayed, so he asked, "What prevented you?" They said, "We prayed in our tents, thinking that the prayer was not obligatory in the mosque." They prayed in their tents, or perhaps the tents were far away, so they thought the prayer had ended. In any case, this is a specific case and cannot be used as evidence that congregation is not obligatory in the mosque, as some people have argued, saying this is proof that congregation is not obligatory in a mosque, because these two men said, "We prayed in our tents," and the Prophet (peace and blessings be upon him) did not rebuke them; rather, he said . The apparent meaning of the hadith is that one prays with the imam according to the imam's prayer. If one limits himself to the two rak'ahs he caught, or if he caught only one rak'ah and performs one to complete the two, I hope there is no harm in that. This is because the prayer, as the Prophet (peace and blessings be upon him) said, . A person is on two rak'ahs if he does not contradict his imam. And when the imam concludes the prayer, what you make up after his taslim does not contradict him. So the summary of the answer is that the best is to complete the four, and if you limit yourself to two rak'ahs, I hope there is no harm in that.