The Fourth Interiour Sense

Know that the words of the Qur’án have an exterior (sense), and under the exterior (sense) an interior (sense), exceedingly overpowering;
And beneath that inward (sense) a third interior (sense), wherein all intellects become lost. The fourth interior (sense) of the Qur’án none hath perceived at all, except God the peerless and incomparable.
In the Qur’án do not thou, O son, regard (only) the exterior: the Devil regards Adam as naught but clay.
The exterior (sense) of the Qur’án is like a man's person, for his features are visible, while his spirit is hidden.
A man's paternal and maternal uncles (may see him) for a hundred years, and of his (inward) state not see (so much as) the tip of a hair.

The Masnawi Volume 3, 4244