The Chief of Forgiveness (Sayyidul Istighfar)
اللَّهُمَّ أَنْتَ رَبِّي لَا إِلَهَ إِلَّا أَنْتَ خَلَقْتَنِي وَأَنَا عَبْدُكَ وَأَنَا عَلَى عَهْدِكَ وَوَعْدِكَ مَا اسْتَطَعْتُ أَعُوذُ بِكَ مِنْ شَرِّ مَا صَنَعْتُ أَبُوءُ لَكَ بِنِعْمَتِكَ عَلَيَّ وَأَبُوءُ لَكَ بِذَنْبِي فَاغْفِرْ لِي فَإِنَّهُ لَا يَغْفِرُ الذُّنُوبَ إِلَّا أَنْتَ
Allahumma anta Rabbi la ilaha illa 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 'alayya, wa abu'u laka bidhanbi faghfir li fa innahu la yaghfirudh-dhunuba illa Anta.
"O Allah, You are my Lord, there is none worthy of worship but You. You created me and I am Your slave. I keep Your covenant, and my pledge to You so far as I am able. I seek refuge in You from the evil of what I have done. I admit to Your blessings upon me, and I admit to my misdeeds. Forgive me, for there is none who may forgive sins but You."
Sahih Al-Bukhari 6306
Spiritual Benefits
Known as the 'Chief of Prayers for Forgiveness', this dua encompasses the ultimate submission to Allah. The Prophet (PBUH) stated that whoever recites it during the day or night with firm faith and dies, they will certainly be among the people of Paradise.
When Should I Say This Dua?
It is highly recommended to recite this once in the morning after Fajr and once in the evening after Maghrib.
Proper Etiquette (Sunnah)
Recite it slowly, pondering over the heavy meaning of the words. It is best said while in a state of Wudu, facing the Qibla.