Allah says;

[قُلْ أَرَءَيْتُمْ إِنْ أَصْبَحَ مَآؤُكُمْ غَوْراً]

(Say: "Tell me! If your water were to sink away...'') meaning, if it were to go away, disappearing into the lowest depths of the earth, then it would not be reachable with iron axes nor strong arms. `Gha'ir' (sinking) as used here in the Ayah, is the opposite of springing forth. This is why Allah says,

[فَمَن يَأْتِيكُمْ بِمَآءٍ مَّعِينٍ]

(who then can supply you with flowing water) meaning, springing forth, flowing, running upon the face of the earth. This means that no one is able to do this except Allah. So, it is merely out of His favor and His grace that He causes water to spring forth for you, and He makes it run to the various regions of the earth in an amount that is suitable for the needs of servants, be it little or abundant. So Allah's is all the praise and thanks. This is the end of the Tafsir of Surat Al-Mulk and all praise and thanks are due to Allah.