Sotah7: 3
מִקְרָא בִכּוּרִים כֵּיצַד? ”וְעָנִיתָ וְאָמַרְתָּ לִפְנֵי ה› אֱלֹהֶיךָ”, וּלְהַלָּן הוּא אוֹמֵר: ”וְעָנוּ הַלְוִיִּם וְאָמְרוּ”, מָה עֲנִיָּה הָאֲמוּרָה לְהַלָּן, בִּלְשׁוֹן הַקֹּדֶשׁ — אַף כָּאן בִּלְשׁוֹן הַקֹּדֶשׁ
From where [is it derived that] the recitation of [the passage] of the first-fruits [must be in Hebrew]? [With respect to the passage of the first-fruits it is stated:] Then you shall speak up and say before HASHEM, your God (Deut. 26:5), and over there it states: and the Levites shall speak up and say (Deut. 27:14). Just as the speaking up stated over there [means] in the Holy Tongue, here too [it means] in the Holy Tongue.