It wasnarrated from 'Ali that whenever the Prophet (ﷺ) prostratedhewould say:
"Allahumma laka sajadtu, wa bika amantu, wa lakaaslamtu, Anta rabbi, sajada wajhi lilladhi shaqqa sam'ahu wabasarahu,tabarak Allah ahsanul-khaliqin (O Allah, to You I haveprostrated, andin You I have believed, and to You I have submitted.You are my Lord;my face has prostrated to the One Who gave ithearing and sight.Blessed is Allah the best of Creators)."*
English reference: Vol. 1, Book 5, Hadith 1054
Arabic reference: Book 5, Hadith 1107