I would offer a very simple one "Don't directly or indirectly attack us or the Pyramids won't need a nightlight for about a 1000 years"
Yeah, I'm sure that the Egyptians are deploying heavy infantry along one of the invasion routes just to address the smuggling problem.
That must be it.
Wouldn't make sense to just search cars, or to create a no-go zone miles deep along the border, with one auto route in and out to the Gaza strip.
Egypt is planning to attack Israel.
This is the culmination of years of policy, which involves (wittingly or unwittingly) the decades of terrorism (which includes the Intifadas), Oslo, joint development of at least one gas field with Gaza, and of course, the outrageous birth rate in Egypt.
Gotta do somethin' with all that cannon fodder.
They are letting the cat guard the cream.