From which one can understand in the Moral sense that in the most secret things we ought to have but little company.
The fourth sense is termed Mystical, that is, above sense, supernatural; and this it is, when spiritually one expounds a writing which even in the Literal sense by the things signified bears express reference to the Divine things of Eternal Glory; as one can see in that Song of the Prophet which says that by the exodus of the people of Israel from Egypt Judaea is made holy and free.

That this happens to be true according to the letter is evident.

Not less true is that which it means spiritually, that in the Soul's liberation from Sin (or in the exodus of the Soul from Sin) it is made holy and free in its powers.
But in demonstrating these, the Literal must always go first, as that in whose sense the others are included, and without which it would be impossible and irrational to understand the others.

Especially is it impossible in the Allegorical, because, in each thing which has a within and a without, it is impossible to come to the within if you do not first come to the without.

Wherefore, since in books the Literal meaning is always external, it is impossible to reach the others, especially the Allegorical, without first coming to the Literal.
Again, it is impossible, because in each thing, natural and artificial, it is impossible to proceed to the form without having first laid down the matter upon which the form should be.