One book which God will open is the book of the Scripture, and will judge men out of it. The word has a double work - to teach, and to judge. It is of divine inspiration. The oracles of Scripture must be surer to us than a voice from heaven. Unbelief enervates the virtue of Scripture, and renders it ineffectual.
First men question the truth of the Scripture, and then fall away from it.
All true solid comfort is fetched out of the word. The word, as Chrysostom says, is a spiritual garden, and the promises are the fragrant flowers or spices in this garden. They only who come to the word with delight, go from it with success. The word, locked up in the heart, is a preservative against sin. As one would carry an antidote about him when he comes near a place infected, so David carried the word in his heart as a sacred antidote to preserve him from the infection of sin.