وَواعَدنا موسىٰ ثَلاثينَ لَيلَةً وَأَتمَمناها بِعَشرٍ فَتَمَّ ميقاتُ رَبِّهِ أَربَعينَ لَيلَةً ۚ وَقالَ موسىٰ لِأَخيهِ هارونَ اخلُفني في قَومي وَأَصلِح وَلا تَتَّبِع سَبيلَ المُفسِدينَ

We set a meeting with Moses for thirty nights, which We completed with another ten; so the term of his Lord was completed in forty nights. Moses instructed his brother Aaron, “Take my place among my people, act rightly, and don’t follow the way of the mischief-makers.”