Leviticus 11:36

“Nevertheless, a fountain or pit, [wherein there is] plenty of water, etc.] Or, “a fountain or pit, a collection of waters”, the copulative being wanting, as some observe, Aben Ezra takes notice of; or it may be by way of apposition, and so may explain what fountain or pit is meant, even such an one where there is a large continence of water, into which, if any carcass of a creeping thing fell, or any part of it, yet it shall be clean: and fit for use, either because of the abundance of water in it, which could not be affected with the fall of such a creature into it as where there is but a small quantity; or rather this exception was made, because pools of water were of considerable value in…”

“Of this no reason can be given, but the will of the law - giver and his merciful condescension to men's necessities, water being scarce in those countries; and for the same reason God would have the ceremonial law of sacrifices, give place to the law of mercy. Leviticus 11:37”

“11:36 A cistern was a hole dug into the ground or rock, often lined with plaster, that retained rain and surface water.”

“a fountain: Zac 13:1; Joh 4:14 wherein there is plenty of water: Heb. a gathering together of waters Leviticus 11:37”