Qur'an 18:77

فَٱنطَلَقَا حَتَّىٰٓ إِذَآ أَتَيَآ أَهْلَ قَرْيَةٍ ٱسْتَطْعَمَآ أَهْلَهَا فَأَبَوْا۟ أَن يُضَيِّفُوهُمَا فَوَجَدَا فِيهَا جِدَارًا يُرِيدُ أَن يَنقَضَّ فَأَقَامَهُۥ ۖ قَالَ لَوْ شِئْتَ لَتَّخَذْتَ عَلَيْهِ أَجْرًا

So they twain journeyed on till, when they came unto the folk of a certain township, they asked its folk for food, but they refused to make them guests. And they found therein a wall upon the point of falling into ruin, and he repaired it. (Moses) said: If thou hadst wished, thou couldst have taken payment for it.