The seventh perek of Massekhet Sota, which begins on today’s daf , teaches the halakha that the warning given to a woman who is suspected of adultery can be given be-khol lashon – “in any language”; it does not need to be said in the language that it is written in the Torah. This teaching leads the Mishna to list a number of formal statements that can be made in any language (for example, the recitation of Shema, Grace after meals, various vows made in court) and some that can only be said in the original Hebrew text (such as a Priestly blessing, a halitza, the speech made by the kohen before leading the army into battle).
The notion that some statements can be made be-khol lashon – “in any language” – follows Rashi’s reading of the Mishna. According to Tosafot (and, among other places, the reading that appears in the Talmud Yerushalmi ) the correct reading is bi-leshonam, “in their language”. Tosafot explain the difference between the variant readings as follows: According to Rashi’s text, it makes absolutely no difference what language is used, while according to Tosafot, if the reading is not done in the original Hebrew, it must be said in a language that will be understood by the listener.
In fact, the cases listed in the Mishna do not encompass all of the situations where a foreign language can be substituted for the original Hebrew. Tosafot explain that the only cases mentioned are those where the principals involved must understand what is being said, so the halakha allows for the statement to be made in a way that is comprehensible to them. This is opposed to acts that are done primarily for ritual purposes, and we are less concerned with being sure that everyone understands what is being said.