Abu Dawud Book 2, Hadith Number 1268.
Narated By Khuraib, the client of Ibn ‘Abbas : ‘Abd Allah b. ‘Abbas, Abd al-Rahman b. Azhar and al-Miswar b. Makhramah sent him to ‘Aisha, wife of the Prophet (PBUH). They said: Convey our regards to her from all of us and ask her about the two rak’ahs after the afternoon prayer; and tell her that we have been informed that she prays them; and we are told that the Apostle of Allah (PBUH) prohibited them. I entered upon her and told her that for which they had sent me. She said: Ask Umm Salamah. I returned to them Ibn ‘Abbas and others) and informed them about her opinion. They sent me back to Umm Salamah with the same mission for which they had sent me to ‘Aisha. Umm Salamah said: I heard the Apostle of Allah (PBUH) prohibiting them, but I later on saw him praying them. When he prayed them, he had offered the afternoon prayer. He then came to me while a number of woman from Banu Haram from the Ansar were sitting with me. He prayed these two rak’ahs. I sent a slave girl to him and I told her: Stand beside him and tell him that Umm Salamah has asked: Apostle of Allah, I heard you prohibiting these two rak’ahs (after the afternoon prayer) but I see you praying them yourself. If he makes a sign with his hand, step backwards from him. The slave-girl did so. He (the Prophet) made a sign with his hand; she turned away from him. When he finished his prayer, he said: O daughter of Abu Ummayah, you asked about praying of two rak’ahs after the afternoon prayer; in fact, some people of ‘Abd al-Qais had come to me with the news their people had embraced Islam. They hindered me from praying the two rak’ahs after the afternoon prayer. It is those two rak’ahs (which I offered after the afternoon prayer).