Genesis 14:13-14

One of the men who was not captured went to Abram, the Hebrew, and told him what had happened. At that time Abram was camped near the great trees of Mamre the Amorite. Mamre was a brother of Eshcol and Aner, and they had all made an agreement to help Abram. When Abram learned that Lot had been captured, he called out his 318 trained men who had been born in his camp. He led the men and chased the enemy all the way to the town of Dan.