Musnad Abu Ya'la al-Mawsili 42:261

Zuhayr narrated to us, Yunus ibn Muhammad narrated to us, Fulayh ibn Sulayman narrated to us, from Sa’id ibn al-Harith, who said: Abu Hurayrah complained [of illness] and was overcome. Abu Sa’id al-Khudri led the prayer, and he raised his voice with the takbir when he began, and when he bowed, and after he said, "Allah hears those who praise Him," and when he raised his head from prostration, and when he prostrated, and when he raised [his head], and when he stood up from the two rak'ahs, until he finished his prayer in that manner. When he finished, it was said to him, "The people have differed regarding your prayer." So he stood up until he stood by the pulpit and said, "O people, by Allah, I do not care whether your prayer differed or did not differ; I saw the Messenger of Allah, may Allah bless him and grant him peace, praying like this."