Charles Spurgeon Commentary Numbers 19:11-12

"He that toucheth the dead body of any man shall be unclean seven days: the same shall purify himself therewith on the third day, and on the seventh day he shall be clean: but if he purify not himself the third day, then the seventh day he shall not be clean." — Numbers 19:11-12 (ASV)

I wonder whether that is a revelation of our being justified through the resurrection of Christ, which took place on the third day after his death, and then our being brought into perfect rest, which represents the seventh day, through the wondrous purifying of our great Sacrifice, the Lamb of God.