Leviticus 15:13

And when he that hath an issue is cleansed of his issue
That is, it is ceased from him, as the Targum of Jonathan and Jarchi explain it; for otherwise, according to the ceremonial law, he was not yet cleansed, until he had done everything next prescribed; but when he perceived there was an entire stop put to his disorder: then he shall number to himself seven days for his cleansing;
by which time it would appear whether he was thoroughly rid of it or not; and these seven days, as Jarchi observes, must be seven pure days, quite free from pollution, and continued in a constant course, without interruption; for, as Gersom says, if he saw any impurity in anyone of these days it did not come into the account: nay, according to Maimonides ^F2, he must begin to number again from the day of the last appearance: and wash his clothes, and bathe his flesh in running water;
typical of the fountain opened in Christ to wash in for sin and uncleanness, even the fountain of his blood, which cleanses from all sin; and in which both the persons and garments of the saints are washed and made white: and shall be clean;
in a ceremonial sense; as all that are washed from their sins in the blood of Christ are clean in a spiritual and evangelical sense.