Hebrews 11:8

Heb. 11:8. 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.

Here, too, Edwards finds evidence

to confirm his (Paul's) doctrine of justification by faith alone, was not Abraham's first act of faith, but was exerted long after he had by faith forsaken his own country, Hebrews 11:8, and had been treated as an eminent friend of God.

The text comes in for mention in Religious Affections in relation to the covenant of grace.

Practice is the most proper evidence of trusting in Christ for salvation. The proper signification of the word "trust," according to the more ordinary use of it, both in common speech, and in the Holy Scriptures, is the emboldening and encouragement of a person's mind, to run some venture in practice, or in something that he does, on the credit of another's sufficiency and faithfulness. And therefore the proper evidence of his trusting, is the venture he runs in what he does. He is not properly said to run any venture, in a dependence on anything, that does nothing on that dependence, or whose practice is no otherwise than if he had no dependence. For a man to run a venture, on a dependence or another, is for him to do something from that dependence by which he seems to expose himself, and which he would not do, were it not for that dependence. And therefore it is in complying with the difficulties, and seeming dangers of Christian practice, in a dependence on Christ's sufficiency and faithfulness to bestow eternal life, that persons are said to venture themselves upon Christ, and trust in him for happiness and life. They depend on such promises as that, "He that loseth his life for my sake, shall find it" (Matthew 10:39). And so they part with all, and venture their all, in a dependence on Christ's sufficiency and truth. And this the Scripture notion of trusting in Christ, in the exercise of a saving faith in him. Thus Abraham, the father of believers, trusted in Christ, and by faith forsook his own country, in a reliance on the covenant of grace God established with him (Hebrews 11:8-9). Thus also "Moses, by faith, refused to be called the son of Pharaoh's daughter, choosing rather to suffer affliction with the people of God, than to enjoy the pleasures of sin for a season" (Hebrews 11:23, etc.). So by faith, others exposed themselves to be stoned, and sawn in sunder, or slain with the sword; endured the trial of cruel mockings and scourgings, bonds and imprisonments, and wandered about in sheep skins, and goat skins, being destitute, afflicted, tormented. And in this sense the apostle Paul, by faith, trusted in Christ, and committed himself to him, venturing himself, and his whole interest, in a dependence on the ability and faithfulness of his Redeemer, under great persecutions, and in suffering the loss of all things; "For the which cause I also suffer these things, nevertheless I am not ashamed; for I know whom I have believed; and I am persuaded, that he is able to keep that which I have committed unto him, against that day" (2 Timothy 1:12).

Heb. 11:9-10