The dealing with a wife over whom her husband was jealous typifies Christ's jealousy over His believers and His church. We must remember that the church and all the believers have a husband—Christ. We may not be rebellious (leprous), we may be quite self-controlled and restrained (not discharging), and our behavior may be altogether right with both God and man, but as a wife to Christ, are we chaste? To be chaste, a wife should not have any love other than her husband. If a wife appreciates any other man, she is on the verge of losing her chastity.
If we are a chaste wife to Christ, we can follow our Husband to fight. David had a fighting wife (1 Sam. 25). In Revelation, Christ's fighting army is composed of His overcomers, who are a fighting wife to match Christ (Rev. 19:7-9, 11-14). In order to be a part of the Lord's fighting army, we must be chaste. The dealings in the book of Numbers show that the requirement for God's people to be formed into an army is very high.
The church and all the believers should have only Christ as their love (2 Cor. 11:2-3). If the church or any of the believers seeks and pursues anything other than Christ, that is spiritual adultery in the eyes of God. Those who commit spiritual fornication will be judged and cursed by God (1 Cor. 16:22) and will not be able to fight for God and serve God. Once we lose our chastity, we lose our ability to fight for God and to serve Him.
The man who was jealous over his wife was to bring her to the priest (Num. 5:15a). The priest here may signify Christ or someone who is very close to God.
"The man shall bring his wife to the priest, and bring her offering for her, a tenth of an ephah of barley meal; he shall pour no oil upon it and put no frankincense on it, for it is a meal offering of jealousy, a meal offering of remembrance, bringing iniquity to remembrance" (v. 15). The priest was then to place this meal offering of jealousy into the hands of the woman (v. 18). The meal offering signifies Christ in His humanity offered to God that God's people may be acceptable. In this case, the meal offering was of barley meal with no oil or frankincense upon it. Barley signifies the resurrected Christ, oil signifies the Holy Spirit, and frankincense signifies resurrection. Such a meal offering of jealousy brought iniquity to remembrance.
"The priest shall present the woman before Jehovah, and unbind the hair of the woman's head" (v. 18a). The unbinding of the woman's hair shows that she has not subjected herself to the headship. The priest also took the holy water (the Holy Spirit) in an earthen vessel (the natural man) and took the dust (the nature of the natural man—Gen. 3:19; Psa. 22:15) from the floor of the tabernacle and put the dust into the water to make it the water of bitterness that brings the curse (Num. 5:17-22).