ἐν τῶ ἱερῷ, not τῷ ναῷ. The latter is Neander’s correction for τῶν ἄνω, “the things above.” Heracleon’s point is that the ἰερόν, the Holy of Holies, represents the spiritual realm; and that Jesus entered it as being, as well as the ναος, in need of His saving work.