What is meant by His — Exalted be He — saying (... your water were to sink away into the earth)? (Surat Al-Mulk)

The meaning of Allah Almighty's saying: (Say, "Have you considered: if your water was to become sunken into the earth, then who could bring you flowing water?") is that your water has become sunken deep into the earth, so far that it cannot be extracted. So, who other than Allah can bring you water that is visible to the eyes and easy to access? This verse is a discourse to the disbelievers, censuring their lack of faith in a Lord who is capable of all things.