Genesis 14:13-14

And there came one that had escaped, and told Abram the Hebrew: now he dwelt by the oaks of Mamre, the Amorite, brother of Eshcol, and brother of Aner; and these were confederate with Abram. And when Abram heard that his brother was taken captive, he led forth his trained men, born in his house, three hundred and eighteen, and pursued as far as Dan.