פִּ֭י יְדַבֵּ֣ר חָכְמ֑וֹת וְהָג֖וּת לִבִּ֣י תְבוּנֽוֹת׃
내 입은 지혜를 말하겠고 내 마음은 명철을 묵상하리로다
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.