Quran 7:142 from Surah Al-A'raaf on Divine Marvels.
۞وَوَٰعَدۡنَا مُوسَىٰ ثَلَٰثِينَ لَيۡلَةٗ وَأَتۡمَمۡنَٰهَا بِعَشۡرٖ فَتَمَّ مِيقَٰتُ رَبِّهِۦٓ أَرۡبَعِينَ لَيۡلَةٗۚ وَقَالَ مُوسَىٰ لِأَخِيهِ هَٰرُونَ ٱخۡلُفۡنِي فِي قَوۡمِي وَأَصۡلِحۡ وَلَا تَتَّبِعۡ سَبِيلَ ٱلۡمُفۡسِدِينَ
English translation: And We appointed (for) Musa thirty nights and We completed them with ten (more) so was completed (the) set term (of) his Lord (of) forty night(s) And said Musa to his brother Harun Take my place in my people and do right and (do) not follow (the) way (of) the corrupters
Transliteration: wawa'adna musa thalathina laylatan wa-atmamnaha bi'ashrin fatamma miqatu rabbihi arba'ina laylatan waqala musa li-akhihi haruna ukh'luf'ni fi qawmi wa-aslih wala tattabi' sabila al-muf'sidina