Firstborn, in a supreme sense, represents the Lord as to divine celestial love, and also peope who were of the celestial church. The sanctification of the firstborn, as in Exodus 13, signifies faith in the Lord. The firstborn, in the spiritual sense of the Word, is good, for with infants the good of innocence is first infused by the Lord, by virtue of which man first becomes a man. Since good is of love, and man does not reflect upon his own love, but only upon the thoughts of his memory, and since good has not at first a quality, but acquires one when it is formed in truths, and without a quality nothing is perceived, hence it was unknown that good was the primary principle, or firstborn. Good is first conceived from the Lord in man, and is produced by truths, in which good is manifested, in its own form and effigy. Firstborn, as in Psalm 89:28, signifies the Lord's humanity.

6305. 'And I give you one portion above your brothers' means that the truth belonging to the understanding and the good belonging to the will were to have more there. This is clear from the representation of Ephraim and Manasseh - who are meant here by Joseph, as they are above in 6275 - as the truth belonging to the understanding and the good belonging to the will, dealt with many times before; and from the meaning of 'giving one portion above their brothers' as having more there, that is to say, in the Church, meant by 'the land', 6304. The reason why the good belonging to the will and the truth belonging to the understanding were to have more there is that these two are the essential constituents of the Church. This also explains why the birthright passed to Joseph's sons, 1 Chronicles 5:1.