en_tn_condensed/psa/036/010.md

Extend your covenant faithfulness fully to those who know you

The writer speaks of Yahweh continuing to act faithfully towards the people as if Yahweh were to extend his covenant faithfulness or make it longer. The abstract noun "faithfulness" can be translated with an adverb. Alternate translation: "Continue to act faithfully to those who know you" (See: rc://en/ta/man/translate/figs-metaphor and rc://en/ta/man/translate/figs-abstractnouns)

your defense to the upright of heart

The abstract noun "defense" can be stated as a verb. "Continue" is implied from the previous phrase. Alternate translation: "Continue to protect the upright of heart" (See: rc://en/ta/man/translate/figs-abstractnouns and rc://en/ta/man/translate/figs-ellipsis)

the upright of heart

Here "heart" refers to the people. Alternate translation: "the upright" or "people who act righteously" (See: rc://en/ta/man/translate/figs-synecdoche)