﴿ قُلْ أَرَءَيْتُمْ إِنْ أَصْبَحَ مَآؤُكُمْ غَوْرًۭا فَمَن يَأْتِيكُم بِمَآءٍۢ مَّعِينٍۭ ﴾

“Say [unto those who deny the truth]: "What do you think? If of a sudden all your water were to vanish underground, who [but God] could provide you with water from [new] unsullied springs?"”

(Say) to them, O Muhammad: (Have ye thought) O people of Mecca: (If (all) your water) i.e. Zamzam (were to disappear into the earth) out of your reach, (who then could bring you gushing water) within your reach? It is also said that this means: who could bring you gushing water save the Creator of the whale and the pen'.