Musnad Ahmad 435:39

'Abd al-Razzaq and Ibn Bakr narrated to us, they said: Ibn Jurayj informed us, he said: 'Umar ibn 'Ata' ibn Abi al-Khuwar informed me that Nafi' ibn Jubayr sent him to al-Sa'ib ibn Yazid, the son of the sister of Namir, to ask him about something Mu'awiyah had seen him do during prayer. He said: "Yes, I prayed Jumu'ah with him in the Maqsura. When he gave the taslim, I stood in my place and prayed. When he entered [his quarters], he sent for me and said: 'Do not repeat what you did. When you pray Jumu'ah, do not connect it with another prayer until you speak or leave, for the Prophet of Allah, peace and blessings of Allah be upon him, commanded that: "Do not connect a prayer with a prayer until you leave or speak."'"