590 – ʿĀʾishah (may Allah be pleased with her) narrated: “I asked, ‘Messenger of Allah, if I come to know which night is the Night of Decree, what should I say during it?’ He replied, ‘Say: Allahumma innaka ʿafuwwun tuḥibbu l-ʿafwa faʿfu ʿannī — O Allah, You are Most Pardoning; You love to pardon, so pardon me.’” It was reported by the Five, apart from Abū Dāwūd, and was declared authentic by al-Tirmidhī and al-Ḥākim. (1)

Status of the ḥadīth
The ḥadīth is authentic.
The author states: al-Tirmidhī and al-Ḥākim authenticated it, and al-Dhahabī agreed with them.
Shaykh Ṣiddīq ibn Ḥasan said in Nuzul al-Abrār: “We have transmitted it with sound chains in the collections of al-Tirmidhī, al-Nasāʾī, Ibn Mājah and others, from ʿĀʾishah (may Allah be pleased with her) who said: ‘I asked, Messenger of Allah ﷺ, if I know which night is the Night of Decree, what do I say in it?’ He replied: ‘Say: Allahumma innaka ʿafuwwun tuḥibbu l-ʿafwa faʿfu ʿannī.’” Al-Tirmidhī commented: “A ḥasan ṣaḥīḥ ḥadīth.”

Points derived from the ḥadīth

1. The Mother of the Believers, ʿĀʾishah (may Allah be pleased with her), eager for the best supplication on that night—knowing that requests are granted and voices are heard—sought guidance from the Prophet ﷺ regarding the finest prayer to offer on Laylat al-Qadr if she were to recognise it. He ﷺ directed her to the most excellent and comprehensive words to say.
2. This supplication was requested by the person dearest to him ﷺ, and he guided her to it as an act of sincere counsel.