Sforno on Genesis 31:53/ספורנו על בראשית ל״א:נ״ג

1אלוהי אביהם, Lavan meant that Yaakov could not take offence at Lavan pairing Nachor’s god and Yaakov’s G’d in a single expression. He had chosen Nachor to underline that Nachor’s god was also the god of Terach, who was the father of both Avraham and Nachor.

2וישבע יעקב בפחד אביו יצחק. He chose someone who was not the son of Terach to make certain it was understood that his oath was only to the G’d of Yitzchok. Only this G’d was entitled to judge him.