It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that Sayyiduna Mu'awiyah (may Allah be pleased with him) prayed Asr, then Sayyiduna Ibn al-Zubayr (may Allah be pleased with them both) stood up and began praying after it. Sayyiduna Mu'awiyah (may Allah be pleased with him) said: "O Ibn Abbas, what are these two rak'ahs?" He said: "It is an innovation, and the one who prays it is an innovator." When Ibn al-Zubayr (may Allah be pleased with them both) finished the prayer, he asked: "What did you two say?" Ibn Abbas (may Allah be pleased with them both) said: "We said such-and-such." Ibn al-Zubayr (may Allah be pleased with them both) said: "I have not introduced any innovation; rather, my maternal aunt, Sayyidah Aishah (may Allah be pleased with her), narrated it to me." So Sayyiduna Mu'awiyah (may Allah be pleased with him) sent a message to Sayyidah Aishah (may Allah be pleased with her), and she said: "He has spoken the truth; the Mother of the Believers, Sayyidah Umm Salamah (may Allah be pleased with her), narrated it to me." Then he sent a message to Sayyidah Umm Salamah (may Allah be pleased with her): "Aishah (may Allah be pleased with her) has narrated such-and-such to us from you?" She said: "She has spoken the truth. One day the Messenger of Allah (peace and blessings be upon him) came to me and prayed after Asr, so I too stood behind him (peace and blessings be upon him) and began to pray. When he (peace and blessings be upon him) finished, he said: 'What is the matter with you?' I said: 'O Prophet of Allah, I saw you praying, so I prayed along with you.' He (peace and blessings be upon him) said: 'A collector of charities (zakah) came to me, and I was concerned about him, so I went to meet him; because of that I forgot to pray the two rak'ahs (of Zuhr) after Asr.'"
Imam al-Tabarani (may Allah have mercy on him) said: "No one narrated this hadith from Qatadah except Sa'id; Zayd bin Yahya bin Ubayd is alone in narrating it."
In the printed Dar al-Haramayn edition it is like this (i.e. "Asr"), and the editor has pointed out that it is so in the manuscript as well, whereas the preserved (correct) word is "Zuhr".
Hadith Referenceالمعجم الأوسط / باب العين / 4125
Hadith Takhrij«أخرجه ابن ماجه فى «سننه» برقم: 1159، وأحمد فى «مسنده» برقم: 26145، 27229، 27293، وابن أبي شيبة فى «مصنفه» برقم: 7424، والطبراني فى «الكبير» برقم: 502، 655، 929»