shall command] The Priest was not to kill the bird, for it was not properly for a sacrifice, since it was to be done far from the Altar, and without the Campe; but for expiation of the leprous person by the sprinkling of the bloud of it upon him.
that one of the birds be killed over running water] Water and bloud are here to be mingled together; for Christ (whose Passion was typified by these sacrifices) came by water and bloud, 1 John 5:6.