כִּֽי־בְשִׂמְחָ֣ה תֵצֵ֔אוּ וּבְשָׁל֖וֹם תּֽוּבָל֑וּן הֶהָרִ֣ים וְהַגְּבָע֗וֹת יִפְצְח֤וּ לִפְנֵיכֶם֙ רִנָּ֔ה וְכָל־עֲצֵ֥י הַשָּׂדֶ֖ה יִמְחֲאוּ־כָֽף׃
For ye shall go out with joy, And be led forth with peace; The mountains and the hills shall break forth before you into singing, And all the trees of the field shall clap their hands.
Ibn Ezra on Isaiah
For you shall go out with joy. You will go out from the exile joyfully.
Rashi on Isaiah
the mountains and the hills shall burst into song before you for they will give you their fruit and their plants, and their inhabitants shall derive benefit. ([Some editions read:] And their inhabitants shall sing.)