Tobit 6:19LXX

17For they who in such manner receive matrimony, as to shut out God from themselves, and from their mind, and to give themselves to their lust, as the horse and mule, which have not understanding, over them the devil hath power.

18But thou when thou shalt take her, go into the chamber, and for three days keep thyself continent from her, and give thyself to nothing else but to prayers with her.

19And on that night lay the liver of the fish on the fire, and the devil shall be driven away.

20But the second night thou shalt be admitted into the society of the holy Patriarchs.

21And the third night thou shalt obtain a blessing that sound children may be born of you.