Musnad Ahmad 30:3183

I read to Abd al-Rahman: Malik, and Ishaq narrated to us, he said: Malik informed us, from Ibn Shihab, from Abu Abdullah al-Agharr, from Abu Hurairah, that the Messenger of Allah, may Allah bless him and grant him peace, said: "Our Lord, the Mighty and Majestic, descends every night to the lowest heaven when the last third of the night remains, and He says: 'Who is calling upon Me, that I may answer him? Who is asking Me, that I may give to him? Who is seeking My forgiveness, that I may forgive him?'"