Palestinian rioters hurled rocks, chairs and fireworks at thousands of Israeli Jews who ascended the flashpoint Temple Mount on Sunday to celebrate Jerusalem Day, amid warnings by the Palestinian Authority that Israel was “playing with fire.” The violence comes ahead of the controversial Flag March, in which Jews armed with Israeli flags march through the Old City of Jerusalem — including the Muslim Quarter — to celebrate the day, which marks the reunification of Jerusalem after Israeli troops recaptured it from Jordanian occupation during the 1967 defensive Six Day War. Some Israelis waved Israeli flags on the Temple Mount, in...