Musnad Ahmad 690:2

'Abd al-Razzaq narrated to us, he said: Sufyan informed us, from Mansur, from Salim ibn Abi al-Ja'd, from a man, from Ka'b ibn Murrah al-Bahzi, who said: I said: "O Messenger of Allah, which part of the night is most heard [i.e., most likely to be answered]?" He said: "The last middle of the night." He said: Then he said: "Then prayer is accepted until the dawn is prayed. Then there is no prayer until the sun is the length of a spear or two spears [above the horizon]. Then prayer is accepted until the shadow stands the length of a spear. Then there is no prayer until the sun passes the meridian. Then prayer is accepted until the sun is the length of a spear or two spears [before setting]. Then there is no prayer until the sun sets." He said: "When you wash your face, your sins exit from your face. And when you wash your hands, your sins exit from your hands. And when you wash your feet, your sins exit from your feet."