לַמְנַצֵּ֥חַ עַֽל־יְדוּת֗וּן מִזְמ֥וֹר לְדָוִֽד׃
פֿאַר דעם געזאַנגמײַסטער, פֿאַר ידותון; אַ מזמור פֿון דָוִדן.
Rashi
on jeduthun The name of a musical instrument. The Midrash Aggadah, though, [explains it to mean]: concerning the ordinances (דתות) and laws that are decreed upon Israel by their enemies.