1 Chronicles 22:9

A son shall be born. Solomon was already married and was a father before the death of David. This is clear from the fact that Solomon reigned 40 years (1 Kings 11:42), and his son Rehoboam was 41 years of age when he began to reign (1 Kings 14:21). Thus Solomon must have been born some considerable time before David’s death, and, if this message came to David before the birth of Solomon, it must have come when David was not much more than halfway through his reign of 40 years.

His name. The name “Solomon” probably means “peaceable.” Hebrew parents attached great significance to the names of their children. Often these names stood for traits of character that the parent desired to see developed in the child (see PK 481). Solomon also had another name, Jedidiah (2 Sam. 12:25), “beloved of Jehovah,” but it was by the name Solomon that he was commonly known.