נְהָר֥וֹת יִמְחֲאוּ־כָ֑ף יַ֝֗חַד הָרִ֥ים יְרַנֵּֽנוּ׃
Let the floods clap their hands; Let the mountains sing for joy together;
Rashi on Psalms
Rivers will clap hands The prophets spoke in a language that the ear can hear; not that the rivers have a hand, but it is an expression of joy and gladness.