Surah 18. Al-Kahf, Ayah 79

Lit., "to cause a fault in it" - i.e., to make it temporarily unserviceable.

They went on the boat, which was plying for hire. Its owners were not even ordinary men who plied for trade. They had been reduced to great poverty, perhaps from affluent circumstances, and deserved great commiseration, the more so as they preferred an honest calling to begging for charity. They did not know, but Khidhr did, that that boat, perhaps a new one, had been marked down to be commandeered by an unjust king who seized on every boat he could get-it may have been, for warlike purposes. If this boat had been taken away from these self-respecting men, they would have been reduced to beggary, with no resources left them. By a simple act of making it unseaworthy, the boat was saved from seizure. The owners could repair it as soon as the danger was past. Khidhr probably paid liberally in fares, and what seemed an unaccountably cruel act was the greatest act of kindness he could do in the circumstances.