Sunan An-Nasa'i

It was narrated from Wasi' bin Habban that:He asked 'Abdullah bin 'Umar about the prayer of the Messenger of Allah (ﷺ). He said: ""Allahu Akbar"" every time he went down and ""Allahu Akbar"" every time he came up, then he said: ""As-salamu 'alaykum wa rahmatullah (peace be upon you and the mercy of Allah) to his right and: As-salamu 'alaykum wa rahmatullah (peace be upon you and the mercy of Allah) to his left