Musnad Ahmad 30:2797

I read to Abd al-Rahman: Malik, and Ishaq narrated to us, he said: Malik narrated to us, from Dawud ibn al-Husayn, from Abu Sufyan, in the hadith of Abd al-Rahman, the freed slave of Ibn Abi Ahmad, that he said: I heard Abu Hurayrah saying: The Messenger of Allah (peace and blessings of Allah be upon him) led us in the Asr prayer, and he performed the taslim after two rak'ahs. Dhu al-Yadayn stood up and said: "Has the prayer been shortened, O Messenger of Allah, or have you forgotten?" The Messenger of Allah (peace and blessings of Allah be upon him) said: "Neither of those happened." He said: "It did happen, O Messenger of Allah." The Messenger of Allah (peace and blessings of Allah be upon him) turned to the people and said: "Is Dhu al-Yadayn telling the truth?" They said: "Yes." The Messenger of Allah (peace and blessings of Allah be upon him) completed what remained of his prayer, then he prostrated two prostrations while he was sitting after the taslim.