What does 2 Samuel 5:16 mean?

This concludes this listing of children born to David while he lived and reigned over Israel in Jerusalem. Elishama, Eliada, and Eliphelet are now added. None of them will play a significant role in the history of Israel. The parallel to this verse is 1 Chronicles 14:7; 1 Chronicles 3:8 is part of the more detailed genealogy.

Aside from genealogies in 1 Chronicles, David's wives and children are mentioned to emphasize how greatly God has blessed him. David had six sons by six different wives when he was king of Judah in Hebron (2 Samuel 3:2–5). He had four more with Bathsheba, including Solomon (1 Chronicles 3:5). And he had nine others with his other wives (1 Chronicles 3:7–9; 14:5–7), two of whom seemed to have died young. This doesn't include David and Maacah's daughter Tamar (2 Samuel 3:3; 13:1) or his many other children from his concubines (1 Chronicles 3:9).

The law of Moses commanded future kings of Israel not to take "many wives" (Deuteronomy 17:17). David's disobedience to this command and the resulting lack of involvement with his children will contribute to sexual assault (2 Samuel 13:1–22), murder (2 Samuel 13:24–33), rebellion (2 Samuel 15-–18), a fight for succession (1 Kings 1:5–53), and an execution (1 Kings 2:19–25), all among his children. None of the men in this verse are involved in the tragic events.

"Elishama" means God the hearer or God has heard. First Chronicles 3:6 calls Elishua (2 Samuel 5:15) Elishama, but it's a different man. Neither is this Elishama the leader of Ephraim when the Israelites entered the Promised Land (Numbers 2:18), the grandfather of one of Gedaliah's murderers (2 Kings 25:25), a priest (2 Chronicles 17:8), nor a secretary (Jeremiah 36:12).

"Eliada" means whom God knows, sees, and cares for. First Chronicles 14:7 calls him Beeliada which means the Lord has known and cared. This isn't Solomon's adversary's son (1 Kings 11:23) or the soldier from Benjamin (2 Chronicles 17:17)

"Eliphelet" means God of salvation. First Chronicles 3:6 mentions a different Eliphelet that 1 Chronicles 14:5 calls "Elpelet," but that son may not have lived to adulthood. Nor is this the same person mentioned in 2 Samuel 23:34, 1 Chronicles 8:39, or Ezra 8:13, 10:33.

This ends the section on how God blessed David by making him king of Israel, establishing his capital in Jerusalem, and giving him a home and a large family (2 Samuel 5:1–16). The account of David's rising fame and glory continues through 2 Samuel 10, starting with his defeat of the Philistines (2 Samuel 5:17–25). From the construction of David's house on (2 Samuel 5:11), it appears the events aren't listed in strict chronological order. For instance, Bathsheba's sons (2 Samuel 5:14) weren't born until after David's sin against her (2 Samuel 11).