A sufi on being asked about ma'arifa (gnosis )...
... the knowledge, upon attaining, you become aware of the limits (of your knowledge).
...for that reason we (may) pray without cease, "rab'bi zidni ilman war zuqni fahman."
'... o master, advance me, by knowledge, and (true) understanding'
-- for that knowledge (of god) which is unattainable, inexhaustible.