For let not that man think that he shall receive anything of the Lord - Compare Hebrews 11:6. A man can hope for favor from God only as he puts confidence in him. He sees the heart; and if he sees that there is no belief in his existence, or his perfections - no real trust in him - no reliance on his promises, his wisdom, his grace - it cannot be proper that he should grant an answer to our petitions. That will account sufficiently for the fact that there are so many prayers unanswered; that we so frequently go to the throne of grace, and are sent empty away. A man that goes to God in such a state of mind, should not expect to receive any favor.

Let not that man think - The man whose mind is divided, who is not properly persuaded either of his own wants or God's sufficiency. Such persons may pray, but having no faith, they can get no answer.

For let not that man think,.... Imagine, conclude, or please himself with such thoughts,
that he shall receive anything from the Lord; wisdom, or anything else, he is seeking after; for wanting faith, he has nothing to receive with; faith is the grace, which receives the Lord Jesus Christ himself, and all grace from him; which receives a justifying righteousness, pardon of sin, adoption of children, and even the everlasting inheritance, at least, the right unto it; wherefore those who have not faith, as the wavering man, cannot receive any thing.

For--resumed from "For" in James 1:6.
that man--such a wavering self-deceiver.
think--Real faith is something more than a mere thinking or surmise.
anything--namely, of the things that he prays for: he does receive many things from God, food, raiment, &c., but these are the general gifts of His providence: of the things specially granted in answer to prayer, the waverer shall not receive "anything," much less wisdom.