'Treasuries' denote knowledge of good and truth, and, in the opposite sense, evil and falsity.

(Reference: Arcana Coelestia 6660)

6267. 'And Joseph took them both, Ephraim in his right hand to Israel's left' means truth belonging to the understanding, to occupy the second place, 'and Manasseh in his left to Israel's right' means good belonging to the will, to occupy the first place. This is clear from the representation of 'Ephraim' as truth belonging to the understanding, and from the representation of 'Manasseh' as good belonging to the will, dealt with in 5354, 6222; and from the meaning of 'the right' as occupying the first place, and of 'the left' as occupying the second place, as is evident from what is the normal practice in life. The implications of all this will be discussed in what follows below.