The abstract noun "faithfulness" can be translated with an adjective. Alternate translation: "you, Yahweh, remain faithful to your covenant forever" (See: [[rc://en/ta/man/jit/figs-abstractnouns]])
This expression probably refers to the people of Israel. God is spoken of as if he had physically used hands to create them. Alternate translation: "the people you have created" (See: [[rc://en/ta/man/jit/figs-metaphor]])