Genesis 1

And why doth He not make it of things that are not? Stopping the mouth of Marcion, and of Manichaeans, who alienate His creation from Him, and teaching by His very works, that even all the things that are seen are His works and creatures, and signifying that it is Himself who gives the fruits, who said at the beginning, "Let the earth put forth the herb of grass," and "Let the waters bring forth things moving with living souls." For this is not at all a less work than the other. For though those were made of things that are not, yet nevertheless were they of water; and it was no greater thing to produce fruits out of the earth, and moving things with life out of the water, than out of five loaves to make so many; and of fishes again, which was a sign that He was ruler both of the earth and of the sea.

Far be it then from us to believe that the couple that were placed in paradise would have fulfilled through this lust, which shamed them into covering those organs, the words pronounced by God in his blessing: "Increase and multiply and fill the earth." For it was only after man sinned that his lust arose; it was after man sinned that his natural being, retaining the sense of shame but losing that dominance to which the body was subject in every part, felt and noticed, then blushed at and concealed that lust. The nuptial blessing, however, whereby the pair, joined in marriage, were to increase and multiply and fill the earth, remained in force even when they sinned. Yet it was given before they sinned, for its purpose was to make it clear that the procreation of children is a part of the glory of marriage and not of the punishment of sin.