יְֽהוָ֗ה בְּעָזְּךָ֥ יִשְׂמַח־מֶ֑לֶךְ וּ֝בִישׁ֥וּעָתְךָ֗ מַה־יגיל [יָּ֥גֶל] מְאֹֽד׃
여호와여 왕이 주의 힘을 인하여 기뻐하며 주의 구원을 인하여 크게 즐거워하리이다
Rashi on Psalms
may the king rejoice with Your strength Our Rabbis (Mid. Ps. 21:1) interpreted it as referring to the King Messiah, but the matter may correctly be interpreted further as referring to David himself, in order to refute the sectarians, who became bold because of it.