Genesis 14:13-14

Then a fugitive came and told Abram the Hebrew. Now he was living by the oaks of Mamre the Amorite, brother of Eshcol and brother of Aner, and these were allies with Abram. When Abram heard that his relative had been taken captive, he led out his trained men, born in his house, three hundred and eighteen, and went in pursuit as far as Dan.