Charles Spurgeon Commentary Numbers 8

These men were to be the servants of God; they are the type of God's elect—a people set apart for divine service, to be zealous for good works. Take the Levites from among the children of Israel, and cleanse them. That is just the way that God the Holy Ghost takes Christians from among mankind, and cleanses them.

And thus shalt thou do unto them, to cleanse them: Sprinkle water of purifying upon them, and let them shave all their flesh, and let them wash their clothes, and so make themselves clean. Then let them take a young bullock with his meat offering, even fine flour mingled with oil, and another young bullock shalt thou take for a sin offering.

There are still, typically, these three things in the cleansing of God's people: the blood, the water, and the razor. There is blood, the emblem of the putting away of sin by Christ's atoning sacrifice; the water, typical of the Holy Ghost, by whom the power of sin is overcome; and then that razor, cutting off what grows of the flesh; what was their beauty and their glory is all taken away from them. There are some of God's people who have not felt much of that razor; but if they are to serve God perfectly, it must be used.

Let them shave all their flesh.

There is no true way of serving God without the atonement.

Leave that out, and you have left out the vital part of the whole.

What service can we render to the Most High if we begin by disloyalty to him whom God has set forth to be the propitiation for sin, even his dear Son?

We are to offer up to God our spirit, soul and body, which is our reasonable service; and if we are indeed God's children, we are to feel that, from now on, we are not our own, for we are bought with a price. We belong wholly to God; all that we are, and all that we have, is to be his through life, and in death, and throughout eternity.

An offering must be presented for us before we can offer ourselves as an offering to God.