Musnad Ahmad 32:1539

Ya'qub narrated to us, my father informed us, from Ibn Ishaq, Ziyad ibn Abi Ziyad, the freed slave of Ibn Abbas, narrated to me, he said: I departed from the Dhuhr prayer, I and 'Umar, when Hisham ibn Isma'il had led the people in it while he was [governor] over Medina, to 'Amr ibn 'Abdullah ibn Abi Talhah to visit him during an illness he had. He said: We did not sit, nor did we ask about him except while standing. He said: Then we departed and entered upon Anas ibn Malik in his house, and it was next to the house of Abu Talhah. He said: When we sat down, the servant girl came to him and said: "The prayer, O Abu Hamzah!" He said: We said: "Which prayer, may Allah have mercy on you?" He said: "The 'Asr." He said: We said: "We have only just prayed the Dhuhr now." He said: So he said: "You have abandoned the prayer until you have forgotten it—or he said: You have forgotten it—until you have abandoned it. Indeed, I heard the Messenger of Allah, peace and blessings of Allah be upon him, say: 'I have been sent, and the Hour is like these two,'" and he extended his index finger and his middle finger.