3493. 'And his eyes were becoming dark so that he could not see' means when the Rational wished to enlighten the Natural from the Divine. This is clear from the meaning of 'the eyes' as interior or rational sight, dealt with in 2701, and from the meaning of 'seeing' as recognizing and understanding, dealt with in 2150, 2325, 2807. Consequently when 'the eyes' are said 'to be becoming dark' the meaning is that no discernment exists any longer, in this case no discernment of the things present in the natural. This being the meaning of these words, the fact that the Rational wished to enlighten the Natural from the Divine is meant. What this implies may be seen from the following things stated and shown already about the rational and the natural with man when he is being regenerated: The rational is regenerated before the natural, for the reason that the rational is interior and so closer to the Divine, and also is purer and so more suited to receiving the Divine than the natural is; and for the further reason that the natural has to be regenerated by way of the rational, see 3286, 3288, 3321.
 When therefore the rational has been regenerated but not the natural the former in that case seems to itself to be made dark, for no correspondence exists between the two. Actually the rational receives its sight from the light of heaven, whereas the natural receives its sight from the light of the world; but unless a correspondence exists between the two the rational is unable to see anything that is in the natural. Everything there is like shadow or even like thick darkness. But once a correspondence does exist, things that are in light in the natural are then apparent to the rational, for things that belong to the light of the world are then enlightened by those that belong to the light of heaven, which are so to speak shining through. But these matters are more clearly evident from what has been stated and shown already about correspondence see 2987, 2989-2991, 3002, 3138, 3167, 3222, 3223, 3225, 3337, 3485. Through what is stated and shown in these paragraphs one may grasp to some extent that the words 'Isaac's eyes were becoming dark so that he could not see' mean that the Rational wished to enlighten the Natural from the Divine, that is to say, to make even the Natural Divine, for the subject in the highest sense is the Lord. Light is thereby shed on this matter by what occurs with man when he is being regenerated and which has been described already; for man's regeneration is an image of the Lord's glorification, 3043, 3138, 3212, 3296, 3490.