Man's primitive charter, according to the earlier chapters of Genesis, was to have dominion over the beasts of the field. Cain knew what it was to war against the wild creatures which contested the possession of the earth with man, and to tame some of them for his uses. And, says the divine voice, just as you war against the beasts of prey, just as you subdue to your purposes and yoke to your implements the tamable animals over which you have dominion, so rule over _this_ wild beast that is threatening you. It is needful for all men, if they do not mean to be torn to pieces, to master the animal that is in them, and the wild thing that has been created out of them. It is bone of your bone and flesh of your flesh. It is your own evil that is thus incarnated there, as it were, before you; and you have to subdue it, if it is not to tyrannise over you. We all admit that in theory, but how terribly hard the practice! The words of our text seem to carry but little hope or comfort in them, to the man who has tried--as, no doubt, many of us have tried--to flee the lusts that war against the soul, and to bridle the animal that is in him. Those who have done so most honestly know best how hard it is, and may fairly ask, Is this useless repetition of the threadbare injunction all that you have to say to us? If so, you may as well hold your tongue. A wild beast sits at my door, you say, and then you bid me, 'Rule thou over it!' Tell me to tame the tiger! 'Canst thou draw out Leviathan with a hook? Wilt thou take him a servant for ever?' I do not undervalue the earnest and sometimes partially successful efforts at moral reformation which some men of more than usual force of character are able to make, emancipating themselves from the outward practice of gross sin, and achieving for themselves much that is admirable. But if we rightly understand what sin is--namely, the taking self for our law and centre instead of God--and how deep its working and all-pervading its poison, we shall learn the tragic significance of the prophets question, 'Can the leopard change his spots?' Then may a man cast out sin from his nature by his own resolve, when the body can eliminate poison from the veins by its own energy. If there is nothing more to be said to the world than this message, 'Sin lieth at thy door--rule thou over it,' we have no gospel to preach, and sin's dominion is secure. For there is nothing in all this world of empty, windy words, more empty and windy than to come to a poor soul that is all bespattered and stained with sin, and say to him: 'Get up, and make thyself clean, and keep thyself so!' It cannot be done. So my text, though it keeps itself within the limits of the law and only proclaims duty, must have hidden, in its very hardness, a sweet kernel of promise. For what God commands God enables us to do.