Nur al-Islaam

Narrated Shaddad bin Aus:
The Prophet said "The most superior way of asking for forgiveness from Allah is: 'Allahumma anta Rabbi la ilaha illa anta, Anta Khalaqtani wa ana abduka, wa ana 'ala ahdika wa wa'dika mastata'tu, A'udhu bika min Sharri ma sana'tu, abu'u Laka bini'matika 'alaiya, wa Abu Laka bidhanbi faghfirli innahu la yaghfiru adhdhunuba illa anta." The Prophet 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."
Bukhari

O you who believe! If you are careful of (your duty to) Allah, He will grant you a distinction and do away with your evils and forgive you; and Allah is the Lord of mighty grace.

O you who believe! be careful of (your duty to) Allah and believe in His Messenger: He will give you two portions of His mercy, and make for you a light with which you will walk, and forgive you, and Allah is Forgiving, Merciful.

And you that ask forgiveness of your Lord, then turn to Him; He will provide you with a goodly provision to an appointed term and bestow His grace on every one endowed with grace, and if you turn back, then surely I fear for you the chastisement of a great day.

11:3