Surah Al-Kahf, ayah 77

18:77

فَٱنطَلَقَا حَتَّىٰٓ إِذَآ أَتَيَآ أَهۡلَ قَرۡيَةٍ ٱسۡتَطۡعَمَآ أَهۡلَهَا فَأَبَوۡاْ أَن يُضَيِّفُوهُمَا فَوَجَدَا فِيهَا جِدَارٗا يُرِيدُ أَن يَنقَضَّ فَأَقَامَهُۥۖ قَالَ لَوۡ شِئۡتَ لَتَّخَذۡتَ عَلَيۡهِ أَجۡرٗا ٧٧

Fantalaqā hattā idhā atayā ahla qaryatinistat'amā ahlahā fa abaw an yudayyifūhumā fawajadā fīhā jidāran yurīdu an yanqadda fa aqāmahū qāla law shi'ta lattakhadhta 'alayhi ajrā

So they set out, until when they came to the people of a town, they asked its people for food, but they refused to offer them hospitality. And they found therein a wall about to collapse, so he [i.e., al-Khiḍr] restored it. [Moses] said, "If you wished, you could have taken for it a payment."