RobH_en_tn/psa/063/011.md

the king will

David is speaking about himself. This can be stated clearly in the translation. Alternate translation: "I, the king of Israel, will" (See: rc://en/ta/man/translate/figs-explicit)

swears by him ... proud of him

The word "him" refers to "God."

but the mouth of those who speak lies will be stopped up

Here "the mouth" represents the whole person. This can be stated in active form. Alternate translation: "but God will silence the liars" or "but God will silence those who lie" (See: rc://en/ta/man/translate/figs-synecdoche and rc://en/ta/man/translate/figs-activepassive)