Musannaf Ibn Abi Shayba 3:978

Ghundar narrated to us, from Shu'bah, from 'Amr ibn Murrah, who said: I heard Ibn Abi Layla, from Abu al-Darda', that he said during his illness in which he died: "Will you not carry me?" So they carried him and brought him out. He said: "Listen and convey to those behind you: Guard these two prayers, the 'Isha' and the Subh (Fajr). If you knew what is in them, you would have come to them even if crawling on your elbows and your knees."