Leviticus 14:5

Over running water - Literally, living, that is, spring water. The meaning appears to be this: Some water (about a quarter of a log, an eggshell and a half full, according to the rabbins) was taken from a spring, and put into a clean earthen vessel, and they killed the bird over this water, that the blood might drop into it; and in this blood and water mixed, they dipped the instrument before described, and sprinkled it seven times upon the person who was to be cleansed. The living or spring water was chosen because it was purer than what was taken from pits or wells, the latter being often in a putrid or corrupt state; for in a ceremony of purifying or cleansing, every thing must be as pure and perfect as possible.

Running water - literally, living water, i. e. water fresh from the spring Genesis 26:19; Numbers 19:17.

14:5 Killed - By some other man. The priest did not kill it himself, because it was not properly a sacrifice, as being killed without the camp, and not in that place to which all sacrifices were confined. In an earthen - vessel - That is, over running water put in an earthen - vessel - Thus the blood of the bird and the water were mixed together, partly forthe conveniency of sprinkling, and partly to signify Christ, who came by water and blood, 5:6 .The running water, that is, spring or river water by its liveliness and motion did fitly signify the restoring of liveliness to the leper, who was in a manner dead before.