And We appointed with Musa a time of thirty nights and completed them with ten (more), so the appointed time of his Lord was complete forty nights, and Musa said to his brother Haroun: Take my place among my people, and act well and do not follow the way of the mischief-makers.

Those who were left behind were glad on account of their sitting behind Allah's Messenger and they were averse from striving m Allah's way with their property and their persons, and said: Do not go forth in the heat. Say: The fire of hell is much severe in heat. Would that they understood (it).