Some XJ's came from the factory with this.  It is only one the driver's side though because it will interfere with how the exhaust is mounted on the passenger's side.  So you could got to a junk yard and try to find one... Good luck because I ever knew that some Xj's have them stock.  Or you could go to a Jeep dealer and see if they have one.  I found a post in 2005 that someone linked this info.  I would imagine that it will be more expensive right now as apposed to 2005.  But here is what he said. 

"you can go to any Jeep dealer and for $17 get the bracket. p/n 52000712 and the interior nut strip (reinforcement) 52001174-5 you need the left or driver side ONLY. $22

Almost any STANDARD hook will work. Mopar wants $75, Harbor Freight $6 "

I guess that it is an L bracket that you will put on right next to the bumper.

This is what some one explained. 

"The flat strips go inside the frame rail, the L brackest bolt the the flat strips under the frame rails and to one bumper bolt. That leaves two re-enforced bolt holes on each side for the hooks. "

No picture was posted though sorry.  Hope that helps.