Lord. — Samuel adds “God.”
Let the thing... be established. — Let the word (promise) be upheld, maintained, assured. Samuel has a different verb, “establish thou.”
Related Commentaries of 1 Chronicles 17:23
1 Chronicles 17:23
23 Therefore now, LORD, let the thing that thou hast spoken concerning thy servant and concerning his house be established for ever, and do as thou hast said.