Thirty Nights, and Ten More

Allah (swt) wanted to meet Mūsā, and He gave Mūsā an appointment to meet Him after thirty days. He said: after thirty days, we meet in the holy place next to al-Ṭūr, next to the mountain. Wa wāʿadnā Mūsā thalāthīna laylah — and We appointed for Mūsā thirty nights.

Mūsā was in a hurry to meet Allah (swt), so he went early. The mufassirūn say that what happened was that Mūsā was commanded to fast for thirty days, because fasting is purification. So Mūsā would go through a period of purification for thirty days before he met Allah (swt). Subḥān Allāh, fasting is a purification — tazkiyah — it is a purification for us. So Mūsā went through that period of purification for thirty days.

Some of the mufassirūn say that because of the smell of his mouth, which is natural due to hunger, Mūsā used a miswāk to change that smell, and he went to meet Allah (swt). Allah told him: O Mūsā, do you not know that I love the smell of the mouth of the person who is fasting more than I love the smell of musk? Go and fast for another ten days. They say that is the reason why Allah (swt) said: and We added ten days to it. So the total was forty days, and during those forty days Mūsā was fasting.

And We appointed for Mūsā thirty nights, and added to the period ten more, and he completed the term appointed by his Lord of forty nights. And Mūsā told his brother Hārūn: replace me among my people, act in the right way, and do not follow the way of the mischief-makers. So the leader of Banū Isrāʾīl was leaving; he had to appoint someone else to lead them, and the best was the nabī Hārūn.