  In this paper we present a real space pairing glue for the iron-based layered
superconductors. It is shown that two static electrons embedded symmetrically
into two adjacent Fe plaquettes of the superconductor can be bounded due to the
Coulombic interaction. The pairing mechanism favors the existence of the
pseudogap in the underdoped FeAs superconductors. A criterion is introduced to
distinguish whether or not the pseudogap can open in a material.
