is itself a form of supplication and therefore a means of having one’s prayer answered—just as Moses (peace be upon him) said: “My Lord, I am truly in need of whatever good You may send down to me.” He appealed to Allah through his very state of need.
“And none forgives sins but You”: this is praise of Allah and an admission of human incapacity, for no one forgives sins except Allah, as He says: “Who forgives sins but Allah?” Even if all mankind joined together to pardon you a single sin, they would be incapable; the only One who can forgive you is Allah.
His words, “forgive me with a forgiveness from Yourself,” attribute the pardon to Allah because that makes it more decisive and more magnificent; the grandeur of the gift corresponds to the greatness of the Giver. “And have mercy on me in what lies ahead; guide me to every good. Indeed, You are the All-Forgiving, the All-Merciful.” Here he is appealing to Allah by two Names that perfectly suit the request: he asked for forgiveness and mercy, so he concluded with “You are the All-Forgiving, the All-Merciful.”
A person should recite this supplication in his prayer, either during prostration or after the final tashahhud. Allah is the One who grants success.
1476 – Abu Musa (may Allah be pleased with him) reported that the Prophet ﷺ would make the following supplication:
“O Allah, forgive me my sin, my ignorance, and my excess in all my affairs, and whatever You know better about than I do. O Allah, forgive me my seriousness and my jest, my accidental and my deliberate (sins); all of that is within me. O Allah, forgive me what I have sent ahead and what I have left until later, what I have done secretly and what I have done openly, and whatever—”