3471. 'They were a bitterness of spirit to Isaac and Rebekah' means that this led at first to grief. This is clear from the meaning of 'bitterness of spirit' as grief, and from the representation of 'Isaac and Rebekah' as the Lord's Divine Rational as regards Divine Good and Divine Truth. For in the highest sense the Lord is the subject, but in the representative sense those who are likenesses and images of Him. That is to say, the highest sense describes how the Lord made His own Human Divine, the representative how the Lord regenerates man, or makes him celestial and spiritual. As regards man's regeneration being the image of the Lord's glorification, see 3043, 3138, 3212, 3296.
[2] The reason why there was grief at first is that when truths are brought into association with natural good they give rise to grief initially since they weigh down the conscience and cause feelings of anxiety owing to the presence of cravings with which spiritual truth conflicts. But this initial grief lessens gradually and at length disappears. It is like the body, when feeble and ill, having to be restored to health by painful remedies. While in that condition it at first suffers pain and grief.