Tertullian — Against Marcion 2.18

But which goods of the law shall I rather defend than those the heresy has struck at? As the definition of talion, demanding eye for eye, tooth for tooth, and bruise for bruise. For it does not savor a license of mutual injury to be practiced, but looks ahead to violence to be wholly restrained—so that, because to a people most hard and unbelieving toward God it seemed long or even incredible to expect defense from God, later to be declared through the prophet: Vengeance is mine, and I will avenge, says the Lord—meanwhile the committing of injury would be dug back by fear of a return about to meet at once, and license of repayment would be a prohibition of provocation.

Thus wickedness, safe from itself, would cease while the second permitted terrifies the first and the first deterred does not even commit the second—whereby also otherwise fear of talion is easier through the taste of the same passion. Nothing is more bitter than to suffer the very thing you have done to others. And if the law takes something away from foods and pronounces unclean animals that were once blessed, understand counsel of practicing continence and recognize bridles imposed on that gluttony which, when it was eating angels’ bread, was longing for Egypt’s cucumbers and melons. Recognize at the same time also provision for gluttony’s companions, namely lust and luxury, which nearly grow cold by chastisement of the belly—for the people had eaten and drunk and risen to play.

Likewise, that the heat of money might also be partly quenched, insofar as it is caused from necessity of living, ambition of precious foods was withdrawn; finally, that a human might more easily be formed to fasting for God, he was habituated to few and not glorious foods, about to hunger for nothing of the richer. The Creator is of course to be blamed because he rather took foods from his people than from more ungrateful Marcionites. Let no one also blame the burdens of sacrifices and the busy scrupulosities of works and offerings as if God properly desired such things for himself—who so openly cries: What to me is the multitude of your sacrifices? and: Who sought these from your hands? But let him sense that industry of God by which he willed to bind a people prone to idolatry and transgression to his religion by such offices with which the age’s superstition was driven, so as to call them away from it, commanding them to be done for himself as if desiring, lest by doing for images they should sin.