Jami` at-Tirmidhi 220
جامع الترمذي#220SahihAbu Sa'eed narrated:"A man came when Allah's Messenger had already prayed, so he said: 'Which of you will give some reward to this person?' So a man stood to pray with him
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih
In-book reference: 2:72