Musnad Ahmad 1421

It was narrated that azZubair bin al-"Awwam (رضي الله عنه) said: I heard the Messenger of Allah (ﷺ) recite this verse when he was in ‘Arafah: "Allah bears witness that La ilaha illa Huwa (none has the right to be worshipped but He), and the angels, and those having knowledge (also give this witness); (He always) maintains His creation in justice. La ilaha illa Huwa (none has the right to be worshipped but He), the All-Mighty, the All-Wise” (Surah AI-‘Imran [3:18]). And I am one of the witnesses to that, O Lord.”