Albert Barnes Commentary 2 Samuel 23:5

"Verily my house is not so with God; Yet he hath made with me an everlasting covenant, Ordered in all things, and sure: For it is all my salvation, and all [my] desire, Although he maketh it not to grow." — 2 Samuel 23:5 (ASV)

Although my house ... - According to the King James Version, the meaning of this clause is that David, comparing the actual state of his family and kingdom during his later years of trouble with the prophetic description of a righteous king’s prosperity, saw how far his own house fell short. He therefore comforts himself with the terms of God’s covenant (2 Samuel 7:12–16) and looks forward to the Messiah’s kingdom. The latter phrase, although he make it not to grow, would then mean that even though the glory of his house was not presently increasing, all his salvation and all his desire were secured in the covenant, which would be fulfilled in due time.

However, most modern commentators understand both clauses as a question: Is not my house so with God that He has made with me an everlasting covenant? They then read the following phrase as another question: For all my salvation and all my desire, will He not cause it to spring up? This "springing up" is understood to refer to the kingdom of Solomon and, even more fully, to the kingdom of Christ.