One of the examples presented by the Mishna (32a) of things that can be said in any language is tefilla – prayer. The Gemara explains simply that since prayer is a heartfelt request from God, a person must be able to express it in any way that he desires.
The Gemara raises an objection to this by pointing to a statement made by Rav Yehuda that a person should not pray in Aramaic, since the heavenly angels cannot understand that language; Rabbi Yoḥanan teaches that if a person prays in Aramaic, his prayers are ignored by the angels since they do not understand Aramaic. The Gemara responds to this question by distinguishing between individual prayer that cannot be in Aramaic, and communal prayer, which can be presented in that language. Rashi explains that since God’s presence resides with the community, there is no need for the intervention of angels, and the prayers can be said even in Aramaic.
Many explanations are offered for the Gemara’s assertion that angels do not understand Aramaic. Tosafot question whether this is true, arguing that angels have the ability to know people’s thoughts, so they certainly can understand people’s spoken words, no matter the language in which they are said. This question leads Tosafot to offer a different interpretation of Rabbi Yoḥanan’s comment. Rather than stating that the angels do not “understand” Aramaic, they suggest that he is saying that they do not have a high opinion of that language. Thus Rabbi Yoḥanan is understood to be saying that the angels will reject prayers offered in Aramaic because they see them as being of little value.
Many commentaries disagree with Tosafot’s line of reasoning. The Sefas Emes, for example, argues with Tosafot’s basic premise and teaches that the Zohar clearly does not believe that angels know the thoughts of men unless they are specifically granted access to that information.