Musnad Ahmad 1156:173

'Abd al-Razzaq narrated to us, he said: Ma'mar narrated to us, from Yahya ibn Abi Kathir, from Abu Salamah ibn 'Abd al-Rahman, from Umm Salamah, the wife of the Prophet, may Allah bless him and grant him peace, who said: "I never saw the Messenger of Allah, may Allah bless him and grant him peace, pray after the 'Asr prayer at all, except for one time. Some people came to him after the Dhuhr prayer and occupied him with something, so he did not pray anything after the Dhuhr prayer until he prayed the 'Asr prayer." She said: "Then when he prayed the 'Asr prayer, he entered my house and prayed two rak'ahs."