Musnad Ahmad 30:3625

'Abd al-Samad and Abu 'Amir narrated to us, they said: Hisham narrated to us, from Yahya, from Abu Ja'far, from Abu Hurairah, that the Messenger of Allah (peace and blessings of Allah be upon him) used to say: "When the last third of the night remains, Allah (Mighty and Majestic is He) descends to the lowest heaven and says: 'Who is it that calls upon Me, that I may answer him? Who is it that seeks My forgiveness, that I may forgive him? Who is it that seeks provision from Me, that I may provide for him? Who is it that seeks the removal of harm, that I may remove it for him?' until the dawn breaks." Abu 'Amir said, from Abu Ja'far, that he heard Abu Hurairah.