לְמַ֛עַן נַסּ֥וֹת בָּ֖ם אֶת־יִשְׂרָאֵ֑ל הֲשֹׁמְרִ֣ים הֵם֩ אֶת־דֶּ֨רֶךְ יְהוָ֜ה לָלֶ֣כֶת בָּ֗ם כַּאֲשֶׁ֛ר שָׁמְר֥וּ אֲבוֹתָ֖ם אִם־לֹֽא׃
이는 이스라엘이 그 열조의 지킨 것 같이 나 여호와의 도를 지켜 행하나 아니하나 그들로 시험하려 함이라 하시니라
Rashi on Judges
Whether they observe. The letter ה is vocalized with the abridged pasach,15This vocalization is used to express inquiry. as it expresses the inquiry involved in testing.
Metzudat David on Judges
IN ORDER TO TEST: It wants to teach that because of this, Hashem chose this punishment, and not others in order to test Israel if they will serve their GD or if not. And this is why its written "if they will guard."