Brethren in Genesis 27:29 signify the affections of good.

(References: Arcana Coelestia 3582)

3583. 'And your mother's sons will bow down to you' means over all other affections for truth. This is clear from the meaning of 'sons' also as truths, dealt with in 489, 491, 533, 1147, 2623, 3373, and from the meaning of 'mother' as the affection for spiritual truth - therefore as the Church, for the Church exists from truth and the affection for this, and is given the name 'mother', dealt with in 289, 2691, 2717.