Sifrei Bamidbar 12

(Bamidbar 5:19) "And the Cohein shall beswear her": The Cohein administers the oath and she does not swear of herself. For it would follow (that she does), viz.: It is written here "swear," and, elsewhere (Vayikra 5:4) "swear." Just as there, he swears of himself, so, here, she should swear of herself. It is, therefore, written "And the Cohein shall beswear her." "and he shall say to the woman": in any language that she understands. These are the words of R. Yoshiyah. For it would follow (otherwise), viz.: If in the instance of yevamah, (the instance) of lesser stringency, the other languages are not equated with the holy tongue (Hebrew) (viz. Devarim 25:9), then, (in the instance of) sotah, the graver instance, how much more so should the other languages not be equated with the holy tongue! It is, therefore, written "and he shall say to the woman" — in any language that she understands. These are the words of R. Yoshiyah. R. Yonathan says: This (derivation of R. Yoshiyah) is not necessary; for it is written (Bamidbar 5:22) "and the woman shall say 'Amen,' 'Amen.'" If she does not understand, how can she say this! — But perhaps she says "Amen" only on the curse (i.e., "to swell the belly, etc." [and not on the oath])! — (This cannot be,) for she says Amen twice — both on the curse and on the oath. What, then, is the intent of "and he shall say to the women" (according to R. Yonathan)? That the Cohein teaches her (the import of) the order of the oath. (5:19) "If no man has lain with you": We are hereby taught that he opens for merit. He says to her: Much wine causes this. Much frivolity causes this. Much childishness causes this. Many have preceded you and been swept away (by lust). Do not allow His great name written in holiness to be erased by the (bitter) waters. He recounts before her things from the tradition, things mentioned in the early writings (Iyyov 15:18) "which wise men relate and which they did not withhold from their fathers." And he says before her things which are not fit to be heard, by her and by all the families of her father's house. R. Yishmael says: In the beginning he apprises her of the strength of the bitter waters. He says to her: My daughter, what are these bitter waters like? Like a dry powder placed on raw flesh, which causes no harm, but which, when it finds a sore spot, penetrates and descends. You, too, if you are clean, drink and do not refrain, and, if you are unclean, in the end you will be swollen by these bitter, blighting waters.