19:1-10 The heifer was to be wholly burned. This typified the painful sufferings of our Lord Jesus, both in soul and body, as a sacrifice made by fire, to satisfy God's justice for man's sin. These ashes are said to be laid up as a purification for sin, because, though they were only to purify from ceremonial uncleanness, yet they were a type of that purification for sin which our Lord Jesus made by his death. The blood of Christ is laid up for us in the word and sacraments, as a fountain of merit, to which by faith we may have constant recourse, for cleansing our consciences.

7. the priest shall be unclean until the even—The ceremonies prescribed show the imperfection of the Levitical priesthood, while they typify the condition of Christ when expiating our sins (2Co 5:21).