Musannaf Ibn Abi Shaybah 38030 — The words of al-Hasan al-Basri

It is narrated from al-Dahhak. He said: Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) wrote to Sayyiduna Abu Musa (may Allah be pleased with him): To proceed: Indeed, strength in work is that you do not postpone today's work until tomorrow. For when you do that, many tasks will pile up upon you, you will not know which of them to take up, and then you will let them go to waste. So when you are given a choice between two matters, one of them for this world and the other for the Hereafter, give preference to the matter of the Hereafter over the matter of this world, for this world is perishing and the Hereafter is lasting. Remain in fear of Allah, and learn the Book of Allah, for it is the springs of knowledge and the springtime of hearts.