Authentic Supplication Number 95.

The Messenger of Allah ¬†used to say in his prostration: ‘Allahumma ‘ighfrlee thambee kullahu, diqqahu wa jillahu, wa ‘awwalahu wa akhirahu, wa `alaniyahu wa sirrahu (113).

(113) O’ my ‘ilah forgive me all my sins; the tiny of them and the greet of them; the first of them and the last of them; the open of them and the secret of them.

Reported by Muslim, and is #78 in The Authentic of Good Sayings.