The Instructor 2.10.91

So too “do not sow on rocks and stones,” says the philosopher who learned from Moses, “where it will never take root and find its fertile nature.” Most clearly the Word commanded through Moses: “You shall not lie with a male as with a woman; for it is an abomination.” And besides, “abstain from every female field” except one's own, the good Plato advised, gathering from the divine Scriptures and taking the law from there: “And you shall not give your bed of seed to your neighbor's wife, to be defiled with her.” “The seed of concubines is unhallowed and bastard.” Do not sow where you would not wish what is sown to grow; and do not touch anyone at all except your own wedded wife, from whom alone it is right to reap the pleasures of the flesh for legitimate descendants. For these alone are lawful by the Word.