Matthew Henry Commentary 2 Samuel 8:15-18

"And David reigned over all Israel; and David executed justice and righteousness unto all his people. And Joab the son of Zeruiah was over the host; and Jehoshaphat the son of Ahilud was recorder; and Zadok the son of Ahitub, and Ahimelech the son of Abiathar, were priests; and Seraiah was scribe; and Benaiah the son of Jehoiada [was over] the Cherethites and the Pelethites; and David`s sons were chief ministers." — 2 Samuel 8:15-18 (ASV)

David neither committed wrong, nor denied or delayed justice to anyone. This speaks of his diligent commitment to his duties, and also his readiness to receive all petitions and appeals made to him. He showed no partiality in judgment. In this, he was a type of Christ.

Let us submit to Him, seek His friendship, and consider His service our pleasure, diligently attending to the work He assigns to each of us. David made his sons chief rulers; but all believers, Christ's spiritual seed, are more highly favored, for they are made kings and priests to our God (Revelation 1:6).