The heifer had no defect. This indicates that Christ was perfect.
The heifer had never been under a yoke. This signifies that Christ was never used by anyone, especially by or for God's enemy, Satan.
"You shall give her to Eleazar the priest, and she shall be taken outside the camp and slaughtered before him" (Num. 19:3). Christ was crucified outside the camp (Heb. 13:12), on Calvary, a little mount outside the city of Jerusalem.
"Eleazar the priest shall take some of her blood with his finger, and shall sprinkle some of her blood toward the front of the tent of meeting seven times" (Num. 19:4). On the day of propitiation, the blood of propitiation was brought into the tabernacle (in the middle of the camp) and was sprinkled upon the ark and toward the veil (Lev. 4:5-7; 16:14-15). However, the heifer was slaughtered outside the camp, far away from the tent of meeting, yet the blood was sprinkled seven times toward the front of the tent of meeting.
Her skin, flesh, and blood, with her dung, were to be burned in the sight of the priest (Num. 19:5).
"The priest shall take cedar wood and hyssop and scarlet, and cast them into the midst of the burning of the heifer" (v. 6). Cedar wood signifies Christ in His dignified humanity, hyssop signifies Christ in His humbled humanity, and scarlet signifies redemption in its highest significance. This means that the high and dignified Christ and the lowly and humbled Christ in His redemption were elements put into the composition of the water for impurity.
Numbers 19:9 refers to the ashes of the heifer. The burning of the heifer with the other elements produced ashes, which signify Christ reduced to nothing. These ashes were kept for the water for impurity; it was a purification of sin, or a sin offering.
Verse 17b speaks of running water. Literally, the Hebrew word translated "running" means living. This living water signifies the Holy Spirit in the resurrection of Christ. In the water for impurity, there is the efficacy of Christ's redemption with the washing power of the Spirit of His resurrection.