1) THE ORDER OF PROCEDURES OF THE SOTAH
QUESTION: The Gemara quotes a Beraisa in which the Tana Kama and Rebbi Shimon disagree about whether Mei Sotah which was prepared by placing dirt in the utensil before pouring the water is valid. RASHI (DH Hikdim) explains that according to the Tana Kama, the water must be placed in the utensil first because the verse states, "The Kohen shall take from the dirt that is on the floor of the Mishkan and put it in the water" (Bamidbar 5:17), which implies that the water is placed in the utensil first. The Torah's addition, "The Kohen shall do for her this entire law" (Bamidbar 5:30), teaches that this order must be followed, and if it is not followed the procedure is invalid (that is, the order is "Me'akev").
Why does Rashi need a source to prove that the order is "Me'akev"? The first verse which Rashi cites ("and he shall place it in the water") should suffice to teach that the water must be placed first and that the order is "Me'akev." (KEREN ORAH)
(a) A general rule in all laws of Kodshim is that a procedure written in the Torah is "Me'akev" only when the verse repeats it. The TORAS HA'KENA'OS points out that Rashi may understand that the preparation of the Mei Sotah is considered a matter of Kodshim, and therefore the order would not be "Me'akev" without an additional verse. This is why Rashi writes that there is an additional verse -- the verse of, "The Kohen shall do for her this entire law."
What is Rashi's source that the preparation of the Mei Sotah is considered a matter of Kodshim?
The Toras ha'Kena'os cites the words of Rebbi Yochanan in the Yerushalmi, who says that Mei Sotah becomes Pasul through Linah. (This is also the view of the Rambam in Hilchos Sotah 4:12.) He explains that Rebbi Yochanan maintains that since the water of the Mei Sotah comes from the Kiyor, and the dirt comes from the floor of the Beis ha'Mikdash, there is reason to assume that it has some degree of Kedushah and that is why it is considered like Kodshim and needs an additional verse to teach that the order is "Me'akev."
(See, however, DEVAR SHA'UL to Sotah 20a, who questions the suggestion that Mei Sotah has the status of Kodshim based on the fact that it may be brought to Sha'ar Nikanor and is not disqualified through "Yotzei.")
(b) The TORAS HA'KENA'OS answers further that this rule (that a procedure of Kodshim is "Me'akev" only when the Torah adds a verse) applies only with regard to the actual performance of the procedure itself. The order of procedures, however, is not "Me'akev" -- even for non-Kodshim matters -- unless there is an additional verse to teach that it is "Me'akev."
(See, however, TOSFOS to 17b, DH Kodem, who implies that a verse is needed to teach that every part of the Sotah process is "Me'akev," and not only to teach that the order is "Me'akev." Perhaps acts which are clearly secondary acts and not integral to the Sotah-examination process are "Me'akev" only when the verse says so explicitly.)