Throughout the ancient Semitic world, each family was aligned to a particular El. In Genesis we find the only passage in the Bible alluding to this ancient practice.
The God of Abraham and the God of Nahor, the God of their father, judge between us." So Jacob swore by the Fear of his father Isaac, (Genesis 31:53, RSV)
Just like many of the other verses we have looked at, the translators have "fixed" this text so that it better fits with the monotheistic view. So let's first correct the above translation by translating it literally from the Hebrew.
The Elohim of Abraham and the Elohim of Nahhor, they will judge between us, the Elohim of their father, and Jacob swore with the fear of his father Isaac.
Note that the Hebrew states, "they will judge," not "he will judge," therefore we are looking at two different Elohim, one belonging to Abraham (the ancestor of Jacob) and the other to Nahhor (the ancestor of Laban). Because we are looking at two different Elohim, the Elohim in the phrase "the Elohim of their father" must be used in the plural sense.
In the Septuagint, the phrase "the Elohim of their father" is not found, and may have been added into the text by the Masorites in an attempt to make the Elohim of Abraham and the Elohim of Nahhor appear to be the one and the same Elohim. However, the context implies that they are not one and the same Elohim, because in the verses prior to this Jacob (the descendent of Abraham) and Laban (the descendent of Nahhor) constructed mounds (altars), representing the two Elohim, as witnesses between them.
 A 2,000 year old Greek translation of the Hebrew Bible.