Genesis 14:13-14

13Then one who had escaped came and told Abram the Hebrew, for he dwelt by the terebinth trees of Mamre the Amorite, brother of Eshcol and brother of Aner; and they were allies with Abram.

14Now when Abram heard that his brother was taken captive, he armed his three hundred and eighteen trained servants who were born in his own house, and went in pursuit as far as Dan.