Mukhtasar Bukhari

Narrated from Ummul Momineen Aisha (may Allah be pleased with her) that some Bedouins and harsh-natured people from Arabia used to come to the Messenger of Allah (peace be upon him) and ask: "When will that Hour (the Day of Judgment) come?" The Prophet (peace be upon him) would look towards the youngest among them and say: "If this one lives, old age will not come upon him before the Hour comes upon you, meaning you will die (and death is also a kind of Hour)."