Al-Kahf 18:77

Fantalaqa hattaitha ataya ahla qaryatin istatAAamaahlaha faabaw an yudayyifoohuma fawajadafeeha jidaran yureedu an yanqadda faaqamahuqala law shi/ta lattakhathta AAalayhi ajra

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."

Then, they moved ahead until they came to the people of a town; they asked its people for food, and they refused to host them. Then, they found there a wall tending to fall down. So he (KhaDir) set it right. He (Mūsā) said, “If you wished, you could have charged a fee for this.”