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.

So Musa returned to his people wrathful, sorrowing. Said he: O my people! did not your Lord promise you a goodly promise: did then the time seem long to you, or did you wish that displeasure from your Lord should be due to you, so that you broke (your) promise to me?