Abu Dawud

Narrated Yazid ibn al-Aswad: Yazid prayed along with the Messenger of Allah ﷺ when he was a young boy. When he (the Prophet) had prayed there were two persons (sitting) in the corner of the mosque; they did not pray (along with the Prophet). He called for them. They were brought trembling (before him). He asked: What prevented you from praying along with us? They replied: We have already prayed in our houses. He said: Do not do so. If any of you prays in his house and finds that the imam has not prayed, he should pray along with him; and that will be a supererogatory prayer for him.

Jabir bin Yazid reported on the authority of his father: I said the morning prayer along with the prophet ﷺ at Mina. He narrated the rest of the tradition to the same effect.

Narrated Yazid ibn Amir: I came while the Prophet ﷺ was saying the prayer. I sat down and did not pray along with them. The Messenger of Allah ﷺ turned towards us and saw that Yazid was sitting there. He said: Did you not embrace Islam, Yazid? He replied: Why not, Messenger of Allah; I have embraced Islam. He said: What prevented you from saying prayer along with the people? He replied: I have already prayed in my house, and I thought that you had prayed (in congregation). He said: When you come to pray (in the mosque) and find the people praying, then you should pray along with them, though you have already prayed. This will be a supererogatory prayer for you and that will be counted as obligatory.

A man from Banu Asad bin Khuzaimah asked Abu Ayyub al-Ansari: if one of us prays in his house, then comes to the mosque and finds that the iqamah is being called, and if I pray along with them ( in congregation), I feel something inside about it. Abu Ayyub replied: We asked the Prophet ﷺ about it. He said: That is a share from the spoils received by the warriors (i. e. he will receive double the reward of the prayer).