The Sixth Commandment, Excerpt from Luther’s Large Catechism

Since this commandment is aimed directly at the state of matrimony and gives occasion to speak of the same, you must well understand and mark, first, how gloriously God honors and extols this estate, inasmuch as by His commandment He both sanctions and guards it. Therefore He also wishes us to honor it, and to maintain and conduct it as a divine and blessed estate; because, in the first place, He has instituted it before all others, and therefore created man and woman separately (as is evident), not for lewdness, but that they should [legitimately] live together, be fruitful, beget children, and nourish and train them to the honor of God.

Excerpt from Luther’s Large Catechism