Du’a for forgiveness
O son of Adam, so long as you call upon Me and ask of Me, I shall forgive you for what you have done, and I shall not mind. O son of Adam, were your sins to reach the clouds of the sky and were you then to ask forgiveness of Me, I would forgive you.
اللَّهُمَّ أَنْتَ رَبِّي لا إِلَهَ إِلا أَنْتَ خَلَقْتَنِي وَأَنَا عَبْدُكَ وَأَنَا عَلَى عَهْدِكَ وَوَعْدِكَمَا اسْتَطَعْتُ أَعُوذُ بِكَ مِنْ شَرِّ مَا صَنَعْتُ أَبُوءُ لَكَ بِنِعْمَتِكَ عَلَيَّ وَأَبُوءُ لَكَ بِذَنْبِي فَاغْفِرْ لِي فَإِنَّهُ لا يَغْفِرُ الذُّنُوبَ إِلا أَنْتَ
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
(O Allah! You are my Lord! None has the right to be worshipped but You. You created me and I am Your slave, and I am fiaithful to my covenant and my promise as much as I can. I seek refuge with You from all the evil I have done. I acknowledge before You all the blessings You have bestowed upon me, and I confess to You all my sins. So I entreat You to forgive my sins, for nobody can forgive sins except You.)
Shaddad ibn Aws (radiAllahu anhu) relates that the Prophet (salAllahu alayhi wasalam) said that he (Sayyid al-Istighfar) most superior way of asking for forgiveness from Allah is to say (the above du’a). That “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.”
[sahih al-Bukhari; 8,75,318, at-Tirmidhi; 3393, an-Nasa’i; 5522, Ahmad; 16662]