John Chrysostom

"By faith Abraham when he was called to go out into a place which he should after receive for an inheritance, obeyed; and he went out not knowing whither he went." "By faith": for (tell me) whom did he see to emulate? He had for father a Gentile, and an idolater; he had heard no prophets; he knew not whither he was going. …

Homily on Hebrews 23 ↗

Theophylact of Ohrid

Since the believers from among the Jews looked upon him and the other patriarchs as having received countless blessings, he intends to show that no one has yet received anything. Therefore he says that "by faith Abraham obeyed," having received the command to leave his homeland. For whom did he know, whom could he have imitated? His father was an idolater, he had not heard the prophets. Therefore, to obey God as one speaking the truth about what He promised, and to leave what he possessed, was on his part an act of faith. …

Commentary on Hebrews ↗

Oecumenius

"By faith, Abraham was called." For he would not have followed, if he had not believed that God speaks the truth, to dwell in that land. And the very act of going out was an act of faith. For when God called, he obeyed, believing that he was being called for good. "not knowing where he was going." And the greater aspect of faith is that he did not even know what he was being called to.

The Pseudo-Oecumenian Catena on Hebrews ↗

Thomas Aquinas

580. – Having given an example of faith from the fathers who existed before the deluge, i.e., those who were the fathers of both the Gentiles and the Jews; the Apostle now treats specifically of the fathers who existed after the deluge, namely, the fathers of the Jews. First of all, he gives the example of the faith of Abraham, who was the father of believers; hence, he was the first to receive the seal of faith before the Law. First, he shows what Abraham did; secondly, what Isaac did (v. 20); thirdly, what Jacob did (v. …

Commentary on Hebrews ↗