Musnad Ahmad 1153:2196

Abu al-Nadr narrated to us, he said: al-Ashja‘i narrated to us, from Sufyan, from ‘Alqamah ibn Marthad, from Ibn Buraydah, from ‘Aishah, she said: I said: "O Messenger of Allah, what do you think if I encounter the Night of Decree (Laylat al-Qadr), what should I say in it?" He said: "Say: O Allah, You are Pardoning, You love pardon."