Genesis 31:53

The God of their father. It is known from Joshua 24:2 and from the existence of idols in Laban’s house (Gen. 31:30, 35), that Abraham’s relatives in Mesopotamia worshiped other gods. This might seem to indicate that “the God of Nahor” could not be Jehovah. But it is known also that Nahor “cherished the knowledge and worship of the true God” (PP 171) along with his idolatry. The verb “judge” is in the plural, in seeming support of the view that Laban was speaking of two distinct gods. However, the LXX, the Peshitto, and the Vulgate render “judge” in the singular, recognizing the God of Abraham and the God of Nahor as one. It would seem that Laban was seeking to bring about unity between himself and Jacob, now that separation was inevitable, by calling attention to the fact that their grandfathers, Abraham and Nahor, and great-grandfather Terah worshiped the same God.

The fear of ... Isaac. See on v. 42. Perhaps Moses added this expression to make it clear that Jacob “sware” by Jehovah and not by any of the gods of Nahor.