Sunan an-Nasa'i 1047
سنن النسائي#1047SahihIt was narrated that 'Aishah said:"The Messenger of Allah (ﷺ) often used to say when bowing and prostrating: 'Subhanaka Rabbana wa bi Hamdika, Allahumm aghfirli (Glorfy and praise be to You, our Lord. O Allah, forgive me)
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 ZaiSahih - Agreed Upon
In-book reference: 12:19