Sunan an-Nasa'i 1555
سنن النسائي#1555SahihIt was narrated from Abu Bakrah that:The Prophet (ﷺ) offered the fear prayer with those who were behind him, praying two rak'ahs (with them) and two rak'ahs with those who came after them, so the Prophet (ﷺ) prayed four rak'ahs and the others each prayed two rak'ahs
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiHasan
In-book reference: 18:27