Musannaf Ibn Abi Shaybah 4802 — A man who forgets all the prayers

Sa'id bin al-Musayyib said, concerning a man who forgot to pray a prayer and remembered it at sunset, and he had not yet prayed the prayer of that time either: "If he fears that, if he occupies himself with the forgotten prayer, the prayer of this time will pass, then let him first perform that one."