Hadith: O Lord, forgive me my sin, my ignorance, my excess in all of my affairs, and whatever You are better aware of than me. O Allah, forgive me my sins, my deliberate sins, my ignorant sins, my humorous sins, and all of this I have committed. O Allah, forgive what I have done and what I have left undone, what I have committed secretly and what I have committed openly; You are the Advancer and You are the Delayer, and You have absolute power over everything

عَنِ أَبِي مُوسَى رضي الله عنه، عَنِ النَّبِيِّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ أَنَّهُ كَانَ يَدْعُو بِهَذَا الدُّعَاءِ:
«رَبِّ اغْفِرْ لِي خَطِيئَتِي وَجَهْلِي، وَإِسْرَافِي فِي أَمْرِي كُلِّهِ، وَمَا أَنْتَ أَعْلَمُ بِهِ مِنِّي، اللَّهُمَّ اغْفِرْ لِي خَطَايَايَ، وَعَمْدِي وَجَهْلِي وَهَزْلِي، وَكُلُّ ذَلِكَ عِنْدِي، اللَّهُمَّ اغْفِرْ لِي مَا قَدَّمْتُ وَمَا أَخَّرْتُ، وَمَا أَسْرَرْتُ وَمَا أَعْلَنْتُ، أَنْتَ المُقَدِّمُ وَأَنْتَ المُؤَخِّرُ، وَأَنْتَ عَلَى كُلِّ شَيْءٍ قَدِيرٌ».
[صحيح] - [متفق عليه] - [صحيح البخاري: 6398]

Abu Mūsa (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) used to invoke Allah with this supplication:
"O Lord, forgive me my sin, my ignorance, my excess in all of my affairs, and whatever You are better aware of than me. O Allah, forgive me my sins, my deliberate sins, my ignorant sins, my humorous sins, and all of this I have committed. O Allah, forgive what I have done and what I have left undone, what I have committed secretly and what I have committed openly; You are the Advancer and You are the Delayer, and You have absolute power over everything."
[Authentic hadith] - [Narrated by Bukhari & Muslim] - [Sahih Bukhari - 6398]

Explanation

The following is among the comprehensive supplications of the Prophet (may Allah's peace and blessings be upon him):
"O Lord, forgive me my sin" and my misdeed, and "my ignorant sins" and what I committed unknowingly.
"My excess in all of my affairs", my negligence, and my transgression.
"And whatever You are better aware of than me,"  You know it, O Allah, whereas I forgot it.
"O Allah, forgive me my sins, my deliberate sins," and the sins I committed deliberately and knowingly.
"My seriousness, my humor," and what was done by way of joking and what I committed in both cases.
"And all this I have committed,"  as it collected the mentioned sins and defects.
"O Allah, forgive what I have done" in the past "and what I have left undone" in the future.
"What I have committed secretly" and stealthily, "and what I have committed openly" and publicly.
"You are the Advancer and You are the Delayer."  You make whomever You will of Your creation proceed to Your mercy through Your guidance to what pleases You, and You delay whomever You will from this through forsaking him. None can bring forward what You have delayed, and none can delay what You have put forward.
"And You have absolute power over everything", possessing the absolute ability and the perfect will, You do whatever You will.