Reference : Hisn al-Muslim 44

اللّهُـمَّ لَكَ سَـجَدْتُ 
وَبِـكَ آمَنْـت ، 
وَلَكَ أَسْلَـمْت ، 
سَجَـدَ وَجْهـي للَّـذي خَلَقَـهُ وَصَـوَّرَهُ 
وَشَقَّ سَمْـعَـهُ وَبَصَـرَه ، 
تَبـارَكَ اللهُ أَحْسـنُ الخـالِقيـن
Allāhumma laka sajadtu 
wa bika āmantu, 
wa laka aslamtu, 
sajada waj’hiya lilladhī khalaqahu, wa ṣawwarahu, 
wa shaqqa sam`ahu wa baṣarahu, 
tabārakallāhu 'aḥsanul-khāliqīn.


O Allah, to You I prostrate myself and in You I believe. 
To You I have submitted. 
My face is prostrated to the One Who created it, fashioned it, and gave it hearing and sight. 
Blessed is Allah, the Best of creators

Reference:
Muslim 1/534 and others.

Chapter: While prostrating