I said: “O Messenger of Allah, suppose I know which night is the Night of Decree, what should I say in it?” He said: “Say: O Allah, You are All-Pardoning, and You love pardon, so pardon me.”

Narrated by Aḥmad (no. 26215), al-Tirmidhī (no. 3513, this is his wording), and Ibn Mājah (no. 3850), from the ḥadīth of ʿĀʾishah (may Allah be pleased with her).
The wording of Aḥmad and Ibn Mājah is: “What if I coincide with the Night of Decree...”
Authenticated in Silsilat al-Aḥādīth al-Ṣaḥīḥah (no. 3337) and Ṣaḥīḥ al-Targhīb wa al-Tarhīb (no. 3391).

Brief Explanation of the Hadith

Laylat al-Qadr (the Night of Decree) is the greatest and most honored night of the year in the sight of Allah, Exalted is He. It is a blessed night that Allah has elevated in status and distinguished with immense virtues — among the greatest of which is that worship performed therein is better than the worship of a thousand months. The Companions — may Allah be pleased with them — were deeply eager to attain goodness and to hasten toward every path of obedience. They would ask the Prophet — may Allah’s peace and blessings be upon him — about the deeds that draw them nearer to Allah’s pleasure, hoping thereby to attain virtue, multiplied reward, and the blessings of this blessed night. Among such examples is what was narrated from the Mother of the Believers, ʿĀʾishah — may Allah be pleased with her — that she asked the Prophet — may Allah’s peace and blessings be upon him — about what supplication she should say if she were to witness the Night of Decree.
The Prophet — may Allah’s peace and blessings be upon him — then guided her to this great supplication, so that it may serve as the believer’s provision on that blessed night. It is one of the most concise and comprehensive supplications for goodness, as it contains acknowledgment of Allah’s attribute of pardon and a plea for His vast forgiveness and mercy.
The meaning of this supplication is that the servant admits his shortcomings and expresses his need for his Lord’s pardon, hoping that Allah will erase his sins, conceal his faults in this world and the Hereafter, and avert from him any punishment. It is a comprehensive supplication encompassing the goodness of both this world and the Hereafter. It combines humility, hope, and acknowledgment of Allah’s grace, as it includes asking for pardon and forgiveness — the greatest of what is sought from the Most Generous Lord. Through His pardon, sins are erased, and true happiness and success are attained; hence, it is among the greatest supplications for Laylat al-Qadr, in which acceptance and forgiveness are most earnestly hoped for.
The ḥadīth highlights the great virtue of this supplication and its profound effect in purifying the soul and reviving the heart.
It also reflects ʿĀʾishah’s – may Allah be pleased with her – eagerness to learn and act upon knowledge, and the Prophet’s – may Allah’s peace and blessings be upon him – deep concern to guide his Ummah to that which brings them nearer to forgiveness and Allah’s pleasure.
It also affirms one of the Names of Allah Almighty — al-ʿAfūw (the All-Pardoning) — and indicates the desirability of asking for pardon after striving in worship, in hope of acceptance and forgiveness.
The ḥadīth likewise shows that it is possible to recognize Laylat al-Qadr, as implied by her words, “What if I know which night is the Night of Decree?” and by the Prophet’s – may Allah’s peace and blessings be upon him – approval of her statement.