Sahih Bukhari
Hadith #4293
Narrated 'Aishah (ra):The Prophet (ﷺ) used to say in his bowings and prostrations, ""Subhanaka Allahumma Rabbanã wa bihamdika, Allãhumma ighfirli"" (Glorified be You, O Allah, our Lord! All the praises are for You. O Allah, forgive me)