John Calvin Commentary Leviticus 16:29

"And it shall be a statute for ever unto you: in the seventh month, on the tenth day of the month, ye shall afflict your souls, and shall do no manner of work, the home-born, or the stranger that sojourneth among you:" — Leviticus 16:29 (ASV)

And this shall be a statute for ever. This day of public atonement is now finally mentioned in express terms. The affliction of souls, which receives fuller attention in chapter 23, is also addressed so that the people might more diligently engage in serious penitential meditations and not doubt that they are truly purged before God.

Yet this purging was understood in a sacramental manner: the external ceremony was to be a most unmistakable sign of that atonement by which, in the fullness of time, they were to be reconciled to God.

Therefore, Moses states at some length that this was to be the unique office of the priest; and by this commendation, he exalts the grace of the coming Mediator, so that He may direct the minds of believers to Himself alone.