Clement of Rome

Abraham, styled "the friend," [Isaiah 41:8] was found faithful, inasmuch as he rendered obedience to the words of God. He, in the exercise of obedience, went out from his own country, and from his kindred, and from his father's house, in order that, by forsaking a small territory, and a weak family, and an insignificant house, he might inherit the promises of God. For God said to him, "Get you out from your country, and from your kindred, and from your father's house, into the land which I shall show you. …

Clement's First Letter to the Corinthians, Chapter 10 ↗

Augustine of Hippo

The right thing to do, brothers and sisters, is to believe God before he pays up anything, because just as he cannot possibly lie, so he cannot deceive. For he is God. That's how our ancestors believed him. That's how Abraham believed him. There's a faith for you that really deserves to be admired and made widely known. He had received nothing from him, and he believed his promise. We do not yet believe him, though we have already received so much. …

Sermon 113A.10 ↗

Ambrose of Milan

Abraham represents the mind. In fact Abraham signifies passage. Therefore, in order that the mind, which in Adam had allowed itself to run to pleasure and to bodily attractions, should turn toward the ideal form of virtue, a wise man has been proposed to us as an example to imitate. Actually Abraham in Hebrew signifies "father," in the sense that the mind, with the authority, the judgment and the solicitude of a father, governs the entire person. This mind then was in Haran, that is, in caverns, subject to the different passions. …

On Abraham 2.1-2 ↗

Bede

And the Lord said to Abram, "Go out from your land, and from your kindred, and from your father's house to the land that I will show you. And I will make you into a great nation, and I will bless you, and I will make your name great, and you will be a blessing." For, speaking distinctly, the Lord mentions land, kindred, and father's house. …

Commentary on Genesis (Hexaemeron) ↗