al-Husain bin Hryth الحسين بن حريث · The Book of the Times (of Prayer)

"A man asked the Messenger of Allah (ﷺ) about the times of prayer. He said: 'Pray with me.' So he prayed Zuhr when the sun had passsed its zenith, 'Asr when the shadow of a thing was equal to its height, Maghrib when the sun had set and 'Isha' when the twilight had disappeared." He said: "Then he prayed Zuhr when the shadow of a man was equal in length to his height, 'Asr when the length of a man's…

"The Messenger of Allah (ﷺ) was asked about a man who slept and missed the prayer, or forgot it. He said: 'The expiation for that is to pray it when he remembers it.'"