(77) باب إِذَا قَامَ الرَّجُلُ عَنْ يَسَارِ الإِمَامِ، وَحَوَّلَهُ الإِمَامُ خَلْفَهُ إِلَى يَمِينِهِ، تَمَّتْ صَلاَتُهُ
Narrated Ibn `Abbas:
I prayed with the Prophet (ﷺ) one night and stood on his left side. Allah's Messenger (ﷺ) caught hold of my head from behind and drew me to his right and then offered the prayer and slept. Later the Mu'adh-dhin came and the Prophet (ﷺ) stood up for prayer without performing ablution.
Reference: Sahih al-Bukhari 726
In-book reference: Book 10, Hadith 120
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 1, Book 11, Hadith 693