Al-Kahf 18:21

Wakathalika aAAtharnaAAalayhim liyaAAlamoo anna waAAda Allahi haqqunwaanna asaAAata la rayba feeha ithyatanazaAAoona baynahum amrahum faqaloo ibnooAAalayhim bunyanan rabbuhum aAAlamu bihim qala allatheenaghalaboo AAala amrihim lanattakhithanna AAalayhimmasjida

And similarly, We caused them to be found that they [who found them] would know that the promise of Allāh is truth and that of the Hour there is no doubt. [That was] when they disputed among themselves about their affair and [then] said, "Construct over them a structure. Their Lord is most knowing about them." Said those who prevailed in the matter, "We will surely take [for ourselves] over them a masjid."

And in this way, We made them known to the people (of the city), so that they realize that Allah’s promise is true, and that there is no doubt about the Hour (the Day of Resurrection). When they were disputing among themselves in their matter, they said, “Erect a building over them. Their Lord knows them best.” Said those who prevailed in their matter, “We will certainly make a mosque over them.”