Musannaf Ibn Abi Shayba 3:4969

Ibn Idris narrated to us, from Yazid, from Abdullah ibn al-Harith, who said: I entered with Ibn Abbas upon Muawiyah. Muawiyah seated him upon the throne, then said to him: "What are the two rak'ahs that the people pray after the Asr [prayer]? We did not see the Messenger of Allah (may Allah bless him and grant him peace) pray them, nor did he command them." He [Ibn Abbas] said: "That is what Ibn al-Zubayr gives fatwa to the people about." So he sent for Ibn al-Zubayr and asked him. He said: "Aisha informed me of that." So he sent to Aisha, and she said: "Umm Salamah informed me of that." So he sent to Umm Salamah. I went with the messenger, and he asked Umm Salamah. She said: "May Allah have mercy on her, what did she intend by this? For I had informed her that the Messenger of Allah (may Allah bless him and grant him peace) forbade them. The Messenger of Allah (may Allah bless him and grant him peace) was in my house performing wudu for the Dhuhr [prayer]. He had sent a collector, and the Muhajirun had gathered around him, and their affair had concerned him. Then the door was knocked, so he went out to them and prayed Dhuhr, then sat distributing what he had brought. He remained like that until he prayed Asr. When he finished, he saw Bilal, so he performed the iqamah for the prayer, and he prayed Asr. He entered my house and prayed two rak'ahs. When he finished, I said: 'What are the two rak'ahs I saw you praying after Asr? I have not seen you pray them.' He said: 'The affair of the collector occupied me; I had not prayed them after Dhuhr, so I prayed them [now].'" Ibn al-Zubayr said: "The Messenger of Allah (may Allah bless him and grant him peace) prayed them, so I pray them."