Moreover Abishai the son of Zeruiah killed eighteen thousand Edomites in the Valley of Salt.
1 Chronicles 18:12
Surrounding context
18:11 King David also dedicated these to the LORD, along with the silver and gold that he had brought from all these nations--from Edom, from Moab, from the people of Ammon, from the Philistines, and from Amalek.
18:12 Moreover Abishai the son of Zeruiah killed eighteen thousand Edomites in the Valley of Salt.
18:13 He also put garrisons in Edom, and all the Edomites became David's servants. And the LORD preserved David wherever he went.