Genesis 11:31

Next it is related how Terah with his family left the region of the Chaldeans and came into Mesopotamia and dwelt in Haran. But nothing is said about one of his sons called Nahor, as if Abram had not taken him along with him. For the narrative runs thus: "And Terah took Abram his son, and Lot the son of Haran, his son's son, and Sarah his daughter-in-law, his son Abram's wife, and led them forth out of the region of the Chaldeans to go into the land of Canaan; and he came into Haran, and dwelt there." Nahor and Milcah his wife are nowhere named here.

But afterwards, when Abraham sent his servant to take a wife for his son Isaac, we find it thus written: "And the servant took ten camels of the camels of his lord, and of all the goods of his lord, with him; and arose, and went into Mesopotamia, into the city of Nahor." This and other testimonies of this sacred history show that Nahor, Abraham's brother, had also left the region of the Chaldeans and fixed his abode in Mesopotamia, where Abraham dwelt with his father. Why, then, did the Scripture not mention him when Terah with his family went forth out of the Chaldean nation and dwelt in Haran, since it mentions that he took with him not only Abraham his son but also Sarah his daughter-in-law and Lot his grandson? The only reason we can think of is that perhaps he had lapsed from the piety of his father and brother, and adhered to the superstition of the Chaldeans and had afterwards emigrated there, either through penitence or because he was persecuted as a suspected person.