Tossefta sur Le Deutéronome 6:6

וְהָי֞וּ הַדְּבָרִ֣ים הָאֵ֗לֶּה אֲשֶׁ֨ר אָנֹכִ֧י מְצַוְּךָ֛ הַיּ֖וֹם עַל־לְבָבֶֽךָ׃

Ces devoirs que je t’impose aujourd’hui seront gravés dans ton cœur.

Tosefta Sotah

The blessing of the Hallel, the Shema, and the tefilah (i.e., the Amidah) may be recited in any language (cf. Sot. 7:1). Rebbi says, I say that the Shema may only be recited in the Holy tongue, as it is said (Deut. 6:6), "And these words, etc."