This is the account of Terah. Terah became the father of Abram, Nahor, and Haran. And Haran became the father of Lot.
27. Terah begat Abram . Here also Abram is placed first among his brethren, not (as I suppose) because he was the firstborn; but because Moses, intent on the scope of his history, was not very careful in the arrangement of the sons of Terah. It is also possible that he had other sons.
Here begins the story of Abram, whose name is famous, henceforward, in both Testaments. We have here, I. His country: Ur of the Chaldees. This was the land of his nativity, an idolatrous country, where even the children of Eber themselves had degenerated.
Commenting on Genesis 11:27-32
Now these [are] the generations of Terah: Terah begat Abram, Nahor, and Haran; and Haran begat Lot. (1) He makes mention first of Abram, not because he was the first born, but for the history which properly belongs to him.