Jamieson, Fausset and Brown on 1 Kings 4:5

5. over the officers--that is, the provincial governors enumerated in 1Ki 4:17-19.

principal officer, and the king's friend--perhaps president of the privy council, and Solomon's confidential friend or favorite. This high functionary had probably been reared along with Solomon. That he should heap those honors on the sons of Nathan was most natural, considering the close intimacy of the father with the late king, and the deep obligations under which Solomon personally lay to the prophet.