People always use the name of someone greater than themselves to make a promise with an oath. The oath proves that what they say is true, and there is no more arguing about it.
One of the men who had escaped went to Abram the Hebrew and told him what happened. Abram was camped near the trees of Mamre the Amorite. Mamre, Eshcol, and Aner had made an agreement to help each other, and they had also signed an agreement to help Abram.
So make a promise to me here before God. Promise that you will be fair with me and with my children. Promise that you will be kind to me and this country where you have lived. Promise that you will be as kind to me as I have been to you.”