וְֽהָיָ֗ה כְּעֵץ֮ שָׁת֪וּל עַֽל־פַּלְגֵ֫י מָ֥יִם אֲשֶׁ֤ר פִּרְי֨וֹ ׀ יִתֵּ֬ן בְּעִתּ֗וֹ וְעָלֵ֥הוּ לֹֽא־יִבּ֑וֹל וְכֹ֖ל אֲשֶׁר־יַעֲשֶׂ֣ה יַצְלִֽיחַ׃
And he shall be like a tree planted by streams of water, that bringeth forth its fruit in its season, and whose leaf doth not wither; and in whatsoever he doeth he shall prosper.
Radak on Psalms
And he shall be like a tree: – He compares the good man to a tree planted over the streams of water: and says that the man who departs from evil and does good, lo ! he is as a tree planted upon streams of water which is continually satisfied; so he rejoices continually in his portion whether he have little to eat or much. And the interpretation of streams of water (is) that there is a stream of water on this side and a stream of water on that side, and they will be passing under it and it will be always over them.
Rashi on Psalms
rivulets ruyseys in Old French, (ruisseaux), brooks (as in Ezek. 32:6).