The Chief Form of Seeking Allah's Forgiveness ...

On the authority of Shaddad ibn Aws, may Allah be pleased with him, the Prophet, Sallallahu Alayhi Wa Aalihi Wa Sallam, said, "The chief of prayers for forgiveness is:

Allahumma anta rabbee la ilaha illa ant, khalaqtanee wa-ana AAabduk, wa-ana AAala AAahdika wawaAAdika mas-tataAAt, aAAoothu bika min sharri ma sanaAAt, aboo-o laka biniAAmatika AAalay, wa-aboo-o bithanbee, faghfir lee fa-innahu la yaghfiruth-thunooba illa ant.

'O Allah, You are my Lord, none has the right to be worshipped except You, You created me and I am Your servant and I abide to Your covenant and promise as best I can, I take refuge in You from the evil of which I committed. I acknowledge Your favour upon me and I acknowledge my sin, so forgive me, for verily none can forgive sin except You.'

The Prophet, Sallallahu Alayhi Wa Aalihi Wa Sallam, added, "If somebody recites it during the day with firm faith in it and dies on the same day before the evening, he will be from the people of Paradise and if somebody recites it at night with firm faith in it and dies before the morning he will be from the people of Paradise."