פירוש על במדבר 5:17

מים קדשים HOLY WATER — i.e., water that has become holy through being in the laver. — The water was taken from the laver because that was made of the copper mirrors of the women who had gathered (Exodus 38:8) [at the entrance to the Tent of Meeting] and this woman deviated from their chaste ways. Because they had cherished their husbands’ love in Egypt (cf. Rashi on Exodus 38:8), while this woman depravedly gave herself over to another, she was to be examined through it (Bamidbar Rabbah 9 :14).

מים קדושים, the waters from the basin in front of the sanctuary.

ולקח הכהן מים קדושים בכלי חרש ומן העפר אשר יהיה בקרקע המשכן, “the Priest is to take sacred water in an earthenware vessel, and he shall take from the earth that is at the floor of the Tabernacle, etc.” Why does he have to take water? Because water symbolises the Heaven (the “upper waters”) and from the floor of the Tabernacle, as this symbolises dust, Earth. We have been taught in Sotah 17 that Rava, commenting on the requirement of dust in connection with the procedure involving the Sotah, the woman suspected of marital infidelity, claims that in the event the woman is found innocent (as she claims) she will bear a son similar to Avraham who said of himself: “I am dust and ashes” (Genesis 18,27). If the woman in question was guilty, however, her fate, i.e. death, will be that she returns to “dust.” Thus far the Talmud.