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.

And We have enjoined on man doing of good to his parents; with trouble did his mother bear him and with trouble did she bring him forth; and the bearing of him and the weaning of him was thirty months; until when he attains his maturity and reaches forty years, he says: My Lord! grant me that I may give thanks for Thy favor which Thou hast bestowed on me and on my parents, and that I may do good which pleases Thee and do good to me in respect of my offspring; surely I turn to Thee, and surely I am of those who submit.