'Twins in the womb,' as in Genesis 25:24, signifies that both good and truth, represented by Esau and Jacob, were conceived together.

The natural as to its good is from the good of the rational as a father, and as to its truth from the truth of the rational as a mother. Each of these is called soul, but good is primarily such. (Arcana Coelestia 3299)

In Genesis 38:27, this signifies that good and truth are both elements of the church and are pairs. (Arcana Coelestia 747, 4918)

(Referenser: Arcana Coelestia 3298)

3299. 'And behold, there were twins in her womb' means that the two were conceived simultaneously. This is clear from the meaning of 'twins' as the two, that is to say, good represented by 'Esau' and truth represented by Jacob', and from the meaning of 'in the womb' as conception, dealt with above in 3293. With regard to the two, that is to say, the good and the truth of the natural, being conceived simultaneously, the situation is that anything that is born owes its being (esse) to the father but its manifestation (existere) to the mother. Both are necessary if anything is to come into existence. As regards good the natural is conceived from the good of the rational as the father, and as regards truth from the truth of the rational as the mother, 3286, 3288. It is good that confers life, but it does so through truth. Though both are called the soul good is nevertheless primarily the soul, while truth clothes it in a kind of thin casing or body, so that the good resides within the truth. This is what is meant by 'twins in her womb'.