הָ֤פַךְ יָ֨ם ׀ לְֽיַבָּשָׁ֗ה בַּ֭נָּהָר יַֽעַבְר֣וּ בְרָ֑גֶל שָׁ֝֗ם נִשְׂמְחָה־בּֽוֹ׃
He turned the sea into dry land; They went through the river on foot; There let us rejoice in Him!
Rashi on Psalms
there it rejoiced with it I found: There was a thing with which the sea rejoiced, i.e., that the sea saw the Holy One, blessed be He.