Musannaf Ibn Abi Shaybah 5597 — Friday when the imam delays it until

Abu Bakr bin Amr bin Utbah al-Zuhri says: Al-Hajjaj delayed the Friday prayer. When he led the prayer, Sayyiduna Abu Juhayfah (may Allah be pleased with him) prayed along with him, and afterwards also prayed two rak'ahs. Then he said: O Abu Bakr! I make you a witness that this is the Asr prayer.