You have to be at the airport at 6 AM if your flight leaves at 9 AM. The airport is extremely busy at this hour and you may be subject to extra questioning in the security line (or maybe not....). If you do not have the car you can either take the 485 bus (stops at the Central Bus Station) , the Nesher sherut (10 seat minibus that will pick you up at your hotel, 67 NIS pp, must be booked the previous day ) or a regular taxi.