There is a difference between separation and sanctification. Separation is on the negative side, and sanctification is on the positive side. On the negative side, we separate ourselves from the worldly people. On the positive side, we sanctify ourselves; that is, we give ourselves to God. First we are separated, and then we are sanctified.
Separating, sanctifying, oneself to God should follow the dealing with all the defilements (chapter five). This is logical, for the dealing with defilement should precede the vow of the Nazarite.
The priests, who are such by birth, are ordained by God out of His initiation. A priest must be a Nazarite, a person absolutely for God. This is according to God's ordination. One's becoming a priest is a matter of God's initiation; it does not depend on what the person does but on what God does concerning him.
The Nazarite, who becomes such by a vow, is separated to God by himself out of his initiation. This means that a person is not a Nazarite by birth but can make himself a Nazarite by making a special vow. Thus, the priests are ordained by God out of His initiation, but the Nazarites become such by a vow out of their own initiation. Today we are in the Lord's recovery out of God's initiation and also out of our initiation. Both are needed.
The accomplishment of God's purpose requires man's cooperation to complement God's ordination. This is illustrated by the case of Samuel. Samuel was a Nazarite who complemented the deficient Eli, a priest ordained by God. In his old age Eli had certain deficiencies. However, Samuel, out of his own initiation, came in to fill up the gap caused by Eli's deficiencies and thereby to complement the deficient Eli.