נְהָרוֹת אוֹמְרִים - Rivers Say:
Tehillim 98:8
נְהָרוֹת יִמְחֲאוּ-כָף יַחַד הָרִים יְרַנֵּנוּ
neharot yimchau-chaf yachad harim yeranenu
Let the floods (rivers) clap hands; let mountains rejoice in song together.
The Scripture refers here to the Messianic Age, of which it says, "May he have dominion also from sea to sea, and from the river to the ends of the earth" (v72:8). At that time, the sea will "roar" out of much gladness, and so will "the world, and they who dwell therein."
"Let the rivers clap hands." Those who dwell by the rivers will clap hands out of great happiness. Similarly, the Scripture says, "They clapped their hands, and said: 'Long live the king!'" (Melachim Bet 11:12).
"Let the mountains rejoice in song together." If until now some trees were barren and only the fruit-bearing trees rejoiced in song (cf. v96:12), at the time of the Redemption all trees will bear fruit. Even barren trees on the "mountains" will "rejoice in song together" with other trees.
It says, "The earth is HaShem's, and the fullness thereof, the world and they who dwell in it. For He has founded it upon the seas, and established it upon the rivers" (v24:1,2). Hence the Scripture says here, "Let the seas roar, and its fullness; the world, and they who dwell in it. Let the rivers clap hands; let mountains rejoice in song together." This corresponds to, "He sends forth springs into the valleys; they run between the mountains" (v104:10).
The rivers symbolize the multitudes and the mountains are their leaders. When the people and their leaders are united in serving G-d, they justly clap their hands and sing for joy, for they serve the world and their Creator.
