רָ֘חַ֤שׁ לִבִּ֨י ׀ דָּ֘בָ֤ר ט֗וֹב אֹמֵ֣ר אָ֭נִי מַעֲשַׂ֣י לְמֶ֑לֶךְ לְ֝שׁוֹנִ֗י עֵ֤ט ׀ סוֹפֵ֬ר מָהִֽיר׃
Mein Herz überwallt in schöner Rede: ich weihe meine Worte dem König. Meine Zunge ist der Griffel eines geübten Schreibers.
Rashi on Psalms
My heart is astir In this manner, the Psalmist commenced his song: My heart caused a good theme to swarm within me in your praise, O Torah scholar.
Rashi on Psalms
is astir Heb. רחש, an expression of moving, and so is every expression of swarming and crawling.
Rashi on Psalms
I say, “My works are for a king” This song, which I have founded and composed, I say to one who is fit to be a king, as it is stated (Prov. 8:15): “Kings reign with me.”