Sunan an-Nasa'i — The Book of the Times (of Prayer) — Hadith No: 506
Translation
It was narrated from Anas:"The Messenger of Allah (ﷺ) used to pray 'Asr, then a person could go to Quba'." One of them [1] said: "And he would come to them when they were prayed." The other said: "And the sub was still high." [1] Both Az-Zuhri and Ishaq bin 'Abdullah narrated it from Anas, so the reference is about them