Musannaf Ibn Abi Shayba 33:104

34329. Ishaq ibn Sulayman al-Razi narrated to us, from Abu Ja'far al-Razi, from al-Rabi', who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "Death is sufficient as a deterrent from the world and an encourager toward the Hereafter."