It was narrated that Abu Bakr bin 'Uthman bin Sahl bin Hunaif said:
"I heard Abu Umamah bin Sahl say: 'We prayed Zuhr with 'Umar bin 'Abdul-'Aziz, then we went out and entered upon Anas bin Malik, and we found him praying 'Asr.'" I said: "O uncle, what is this prayer that you prayed?" He said: "'Asr; this is the prayer of the Messenger of Allah (ﷺ) that we used to pray with him."
English reference: Vol. 1, Book 6, Hadith 510
Arabic reference: Book 6, Hadith 513