Everything was in balance between Israel and Egypt until Mubarak was overthrown in a popular uprising early last year. The US continued to give aid to the Egyptian military, but weren't sure if the deal was still in place after the change in government.
The deal, to be clear, was the US gives money to Egypt and the army supports peace with Israel and the people of Egypt are suppressed.
The Israelis desperately wanted to verify that the old deal was still in place. They couldn't test it without some kind of conflict. So they created one. Now we need a cease fire. Secretary Clinton flies to Cairo. Drama. Does the old deal stand? she asks. Morsi asks to have the deal explained. She does. He says sounds good. She asks for proof. What would you like? Announce that you are taking extra-constitutional power. He asks if the money will keep flowing. She says yes. He says OK.
That's what I think happened.
PS: Why would Israel want to know now whether the peace deal with Egypt was still in place? Maybe they're getting ready to attack Iran and want to be sure they don't have to fight Egypt too.