Sahih al-Bukhari — Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi) — Hadith No: 4293
Translation
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)