en_tn_condensed/psa/109/028.md

Though they curse me

The word "they" refers to the people who accuse David and say bad things about him.

may they be put to shame

This can be stated in active form. Alternate translation: "may they be ashamed" or "let them be ashamed" (See: rc://en/ta/man/jit/figs-activepassive)

but may your servant rejoice

"but may I, your servant, rejoice" or "I am your servant, let me rejoice." David uses the phrase "your servant" to refer to himself.