We appointed for Moses thirty nights then added another ten—completing his Lord’s term of forty nights. Moses commanded his brother Aaron, “Take my place among my people, do what is right, and do not follow the way of the corruptors.”

And We appointed for Mûsâ (Moses) thirty nights and added (to the period) ten (more), and he completed the term, appointed by his Lord, of forty nights. And Mûsâ (Moses) said to his brother Hârûn (Aaron): "Replace me among my people, act in the Right Way (by ordering the people to obey Allâh and to worship Him Alone) and follow not the way of the Mufsidûn (mischief-makers)."