Musnad Ahmad 1153:1477

Yazid narrated to us, he said: Al-Jurayri informed us, from Abdullah ibn Buraydah, that Aisha said: "O Messenger of Allah, if I encounter the Night of Decree (Laylat al-Qadr), what should I supplicate with?" He said: "Say: O Allah, You are Pardoning, You love pardon, so pardon me."