פִּ֭י יְדַבֵּ֣ר חָכְמ֑וֹת וְהָג֖וּת לִבִּ֣י תְבוּנֽוֹת׃
Ma bouche prêche la sagesse, et la raison inspire les pensées de mon cœur.
Rashi on Psalms
and the thoughts of my heart are understanding The thoughts of my heart are understanding.
Ibn Ezra on Psalms
"My mouth" - to teach all the wisdom hidden from them, which those wise of heart explain by riddles.
Ibn Ezra on Psalms
And "thoughts and insights" - that my heart thought.