Sunan an Nasai
1047
Sahih+2

It 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)

SahihAbu Ghuddah
SahihAl-Albani