Master dhikr of forgiveness
اللَّهُمَّ أَنتَ ربِّي لا إلَه إلَّا أَنتَ، خَلَقتَنِي وأَنَا عَبدُك وأَنَا عَلَى عَهدِكَ ووَعدِكَ مَا استَطَعت، أَعُوذُ بِكَ مِن شَرِّ مَا صَنَعت، أَبُوءُ لَكَ بِنِعمَتِكَ عَليَّ وأَبُوءُ بِذَنبِي، فَاغفِر لِي، فَإنَّهُ لا يَغفِرُ الذُّنُوبَ إلَّا أَنت
Recommended reading: 3x
O Allāh! You are my Lord, there is no god but You. You created me and I am your slave, and I uphold Your pledge and promise as best as I can. I seek Your protection against the evil that I have committed. I acknowledge Your blessing upon me and I acknowledge my sin. So forgive me, for none can forgive sins except You.
Allāhumma anta rabbi la ilaha illa anta, khalaqtani wa ana 'abduka wa ana 'ala 'ahdika wa wa'dika ma istata'tu, a'udhu bika min sharri ma sana'tu, abu'u laka bini'matika 'alayya wa abu'u bidhanbi, faghfir li, fa innahu la yaghfiru alththunuba illa anta.
من قالها موقنًابها حين يمسى، فمات من ليلته دخل الجنة، وكذلك إذا أصبح
Shaddad ibn Aws (radiAllāhu anhu) relates that the Prophet ﷺ said that he (Sayyid al-Istighfar) most superior way of asking for forgiveness from Allāh 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.”