וַיֹּאמֶר֩ בֹּ֨עַז לַזְּקֵנִ֜ים וְכָל־הָעָ֗ם עֵדִ֤ים אַתֶּם֙ הַיּ֔וֹם כִּ֤י קָנִ֙יתִי֙ אֶת־כָּל־אֲשֶׁ֣ר לֶֽאֱלִימֶ֔לֶךְ וְאֵ֛ת כָּל־אֲשֶׁ֥ר לְכִלְי֖וֹן וּמַחְל֑וֹן מִיַּ֖ד נָעֳמִֽי׃
보아스가 장로들과 모든 백성에게 이르되 내가 엘리멜렉과 기룐과 말론에게 있던 모든 것을 나오미의 손에서 산 일에 너희가 오늘날 증인이 되었고
Siftei Chakhamim
They appointed him to be their judge. You might ask: How does Rashi know that he was a judge? The answer is: It is written he was “sitting at the gate,” and “the gate” is usually the place of judgment, as we find with Boaz (Ruth 4:1). Furthermore, it is written later וישפט שפוט (v. 9), implying he was a judge.