Human nature in its fourfold state ... In several practical discourses

Evid. 5 But however hard it is to keep the mind on good thoughts, it sticks as glue to what is evil and corrupt like itself! 2 Pet. ii. 14. Having eyes full of adultery, and that cannot cease from sin. Their eyes cannot cease from sin; (so the words are constructed) that is, their hearts and minds venting by the eyes, what is within, are like a furious beast, which cannot be held in, when once it has got out its head. Let the corrupt imagination once be let loose on its proper object; it will be found hard work to call it back again, tho' both reason and will be for its retreat. For then it is in its own element; and to draw it off from its impurities, is as the drawing of a fish out of the water, or the renting of a limb from a man. It runs like fire set to a train of powder, that resteth not till it can get no further.

Evid. 6. Consider how the carnal imagination supplies the want of real objects to the corrupt heart; that it may make sinners happy, at least, in the imaginary enjoyment of their lusts. Thus the corrupt heart feeds itself with imagination-sins: the unclean person is filled with speculative impurities, having eyes full of adultery; the covetous man fills his heart with the world, tho' he cannot get his hands full of it; the malicious person, with delight, acts his revenge within his own breast) the envious man, within his own narrow soul, beholds, with satisfaction, his neighbour laid low enough; and every lust finds the corrupt imagination a friend to it in time of need. And this it doth, not only when people are awake, but sometimes even when they are asleep; whereby it comes to pass, that these sins are acted in dreams, which their hearts were carried out after, while they were awake. I know some do question the sinfulness of these things: But can it be thought they are consistent with that holy nature and frame of spirit, which was in innocent Adam, and in Jesus Christ, and should be in every man? It is the corruption of nature then, that makes filthy dreamers condemned, Jude 8. Solomon had experience of the exercise of grace in sleep: in a dream he prayed, in a dream he made the best choice; both were accepted of God,