This is said in the first place because the motion of the world proceeds from the rising of the sun to its setting. And it first exists in that quarter from which it is moved; secondly, because that part of the world which is in the region of the east is called the right side; and that which is in the region of the west is called the left side of the world.
Moreover, the poet bears witness to this, calling the birds from the east dexterous or right, and those on the west sinistral or left; when he says, whether they go to the right to the day and to the sun, or whether they go to the left towards the dusky evening. But the name Eden, when rightly understood, is an indication of all kinds of delights, joys, and pleasures since all good things and all blessings derive their beginning from the place of the Lord. Thirdly, wisdom itself is splendor and light.