John Calvin on Acts 7:8

8. He gave him the covenant. When as he confesseth that circumcision is the covenant of God, he cleareth himself sufficiently of that crime which was laid to his charge; but, in the mean season, he showeth that the Jews deal amiss, if they place the beginning of their salvation in the external sign. For if Abraham was called, and the land and redemption promised to his seed before such time as he was circumcised, it appeareth that the glory of the whole stock cloth not depend upon circumcision. Paul useth the same argument in the 4th chapter to the Romans, (Romans 4:11.) For, seeing that Abraham obtained righteousness, and pleased God before he was circumcised, he gathereth thence that circumcision is not the cause of righteousness. Therefore we see that Stephen frameth no vain and idle narration; because this was very much appertinent unto the cause, that the Jews might remember how God had adopted them with their fathers, and it is to be thought that Stephen did plainly express both things; that although circumcision was given by God, that it might be a sign of grace, yet was the adoption before it both in order and in time. But we have no need to dispute any longer in this place concerning the nature and force of circumcision. Only let us note this, that God doth first promise those things to Abraham which he confirmeth afterward by circumcision, that we may know that the signs are vain and nothing worth, unless the word go before. Let us also note, that there is a profitable doctrine contained in the word covenant, to wit, that God maketh his covenant with us in the sacraments, that he may declare his love toward us; which thing, if it be true, first, they are not only works of external profession amongst men, but they gave great force inwardly before God, to confirm the faith. Secondly, they are no vain figures; because God, who is true figureth nothing there which he doth not perform.

Acts 7:9-16

9. And the patriarchs, moved with envy, sold Joseph into Egypt. Notwithstanding, God was with him; 10. And he delivered him out of all his afflictions: and he gave him favor and wisdom in the sight of Pharaoh, king of Egypt, who made him ruler over Egypt, and over all his house. 11. And there came a famine upon all the land of Egypt and Canaan, and great affliction; neither did our fathers find food. 12. And when Jacob had heard that there was corn in Egypt, he sent our fathers thither first. 13. And at the second coming Joseph was known of his brethren; and the kindred of Joseph was made known to Pharaoh. 14. Then Joseph sent, and called out his father Jacob and all his kindred, seventy-five souls. 15. And Jacob went down into Egypt, and he died, and our fathers; 16. And they were carried into Sychem, and they were laid in the sepulcher which Abraham had bought for money of the sons of Hemor, the son [father] of Sychem.