3129. 'And Rebekah had a brother' means the affection for good in the natural man. This is clear from the meaning of 'a brother' and of 'a sister' in the Word - 'a brother' being the affection for good, and 'a sister' the affection for truth, dealt with in 367, 2360, 2508, 2524. For in the natural man, as in the rational, all things there are interrelated like blood relatives and relatives by marriage, 2556, 2739. For that reason also the rational mind as well as the natural mind is called a house or family where parents, brothers, sisters, blood relatives, and relatives by marriage exist in order.

2740. Genuine conjugial love is not possible except between two married to each other, that is, within the marriage of one man and one wife. It is not by any means possible when one is married simultaneously to many, for the reason that conjugial love is mutual and reciprocal, and the life of one partner is bound up in that of the other, and vice versa, so that they are so to speak one. Such a union is possible between two, but not between many; many split that love apart. Members of the Most Ancient Church, who were celestial and with whom the perception of good and truth existed as with angels, had only one wife. They used to say that with one wife they enjoyed every form of heavenly delight and happiness, and that the mere mention of being married to many horrified them; for the marriage of one husband and one wife is descended, as has been stated, from the marriage of good and truth, or the heavenly marriage, which is of such a nature, as may become quite clear from the Lord's words in Matthew,

Jesus said, Have you not read that He who made them from the beginning made them male and female, and said, For this reason a man (homo) will leave father and mother and will cling to his wife; and the two will become one flesh? Therefore they are no longer two, but one flesh. What therefore God has joined together let not man (homo) separate. For the hardness of your heart Moses allowed you to divorce your wives, but from the beginning it was not so. Not everyone receives this teaching, but those to whom it has been given. Matthew 19:3-12.