Mishkat al-Masabih 2335

Shaddad b. Aus reported God’s messenger as saying that the best manner of asking pardon is to say, “O God, You are my Lord. There is no god but You. You have created me, and I am Your servant and hold to Your covenant and promise as much as I can. I seek refuge in You from the evil of what I have done. I acknowledge Your favour to me, and I acknowledge my sin. Pardon me, for none but You pardons sins.” He said that if anyone says it during the day-time with firm belief in it and dies that day before evening, he will be one of those who go to paradise; and if anyone says it during the night with firm belief in it and dies before morning, he will be one of those who go to paradise. Bukhari transmitted it.