Numbers 19:22

וכל אשר יגע בו הטמא AND WHATSOEVER THE UNCLEAN PERSON TOUCHETH — i.e., this unclean person who has become unclean by reason of a corpse, SHALL TOUCH, יטמא SHALL BECOME UNCLEAN. והנפש הנגעת AND THE SOUL THAT TOUCHETH him that hath become unclean by reason of a corpse, תטמא עד הערב SHALL BE UNCLEAN UNTIL THE EVEN — Here we learn that a corpse is a progenitor of a primary source of uncleanness, and he that touches it becomes a primary source of uncleanness and can render a human being unclean. — This is its explanation (that of the whole chapter) according to what it literally implies and according to the Halachoth connected with it. — A Midrashic explanation I have copied from the work of R. Moses the Preacher, and this is: ויקחו אליך AND THEY SHALL TAKE UNTO THEE — They shall take from that which is their own: just as they divested themselves of their golden earrings for making of the calf — i.e., of that which was their own, so shall they bring this calf-like animal as an atonement from that which is their own. פרה אדמה A RED COW — Why this rite was performed with a cow may be exemplified by a parable it may be compared to the case of a handmaid’s child that defiled the king’s palace. They said: Let the mother come and wipe up the excrement. Similarly here: since they became defiled by a calf, let its mother (a cow) come and atone for the calf (cf. Midrash Tanchuma, Chukat 8). אדמה RED — It had to be red in allusion to the idea contained in the text (Isaiah 1:18): “Though they (your sins) be red as scarlet [they shall become as white as snow]” — so you see that sin is termed red. תמימה PERFECT — in allusion to the Israelites who were perfect but through it (the calf) became morally maimed: let this perfect animal come and atone for them so that they may regain their state of perfection. לא עלה עליה על [A COW] UPON WHICH NEVER CAME A YOKE — just as they cast off themselves the yoke of Heaven. אל אלעזר הכהן TO ELEAZAR THE PRIEST — just as they gathered together against Aaron who was a priest to force him to make the golden calf. But because Aaron had made the calf this rite was not entrusted to him that it should be carried out by him, because the prosecuting counsel cannot become the defending counsel (Rosh Hashanah 26a; cf. Rashi on Leviticus 16:4; Aaron who had caused the sin was not a fitting person to atone for it: therefore the rite had to be performed by another priest, viz., by Eleazar). ושרף את הפרה AND ONE SHALL BURN THE COW, just as the calf was burnt (Exodus 32:20). עץ ארז ואזוב ושני תולעת CEDAR WOOD AND HYSSOP AND CRIMSON — These three species correspond to the three thousand men who fell by the edge of the sword on account of the golden calf. The cedar is the loftiest of all trees and the hyssop the lowliest of all — a symbol that the man of high position who displays pride and on that account falls into sin should make himself as lowly as the hyssop and the worm (תולעת), and he will then gain atonement. למשמרת [IT SHALL BE] KEPT [FOR THE CONGREGATION OF THE CHILDREN OF ISRAEL], just as the transgression of the calf is kept in remembrance for all future generations for punishment, for there is no visitation of Israel in which there is not something of the visitation of the sin caused by the calf, as it is said, (Exodus 32:34) “On the day when I visit I will visit [their sin upon them]” (cf. Rashi on that verse, and Sanhedrin 102a; Yerushalmi Taanit 14). And just as the calf rendered unclean everyone who busied himself with it (cf. Avodah Zarah 32b), so, too, does the cow make unclean all who busy themselves with it. And just as they (Israel) were purified by its dust (Exodus 22:20), similarly it states, (v. 17) “And for an unclean person shall they take of the dust of the burnt cow of purification, etc.”

וְכֹ֛ל אֲשֶׁר־יִגַּע־בּ֥וֹ הַטָּמֵ֖א יִטְמָ֑א וְהַנֶּ֥פֶשׁ הַנֹּגַ֖עַת תִּטְמָ֥א עַד־הָעָֽרֶב׃ {פ}

And whatever the unclean person touches shall be unclean; and the person that touches it shall be unclean until the evening.