Albert Barnes Commentary 2 Samuel 23:36

"Igal the son of Nathan of Zobah, Bani the Gadite," — 2 Samuel 23:36 (ASV)

It is remarkable that we have several foreigners in this part of the list: Igal of Zobah, Zelek the Ammonite, Uriah the Hittite, and perhaps Nahari the Beerothite. The addition of Zelek to the mighty men was probably the fruit of David’s war with Ammon (2 Samuel 8:12; 2 Samuel 10; 2 Samuel 12:26–31).