"When the menstrual purgations appear in the wives, their husbands should not approach them, out of regard to the children to be begotten. For the Law has forbidden it when it says: “You will not come near your wife when she is in her separation” [Lev. 18:19]. Nor, indeed, let them have relations when their wives are with child. For [in that case] they are not doing it for the begetting of children, but only for the sake of pleasure. Now a lover of God should not be a lover of pleasure."