Albert Barnes Commentary 1 Chronicles 17:18

"What can David [say] yet more unto thee concerning the honor which is done to thy servant? for thou knowest thy servant." — 1 Chronicles 17:18 (ASV)

For the honor of your servant - that is, “for the honor which You have done for Your servant.” The Septuagint omits “Your servant” and renders it: “What can David say more to You to glorify You? For You know,” etc.