The tests provided will cost 135nis for results within 4 hours, and will cost 45nis for results within 14 hours.

The testing lab will be available for people leaving Israel traveling to other countries, and for people coming in to Israel from other countries.

People traveling to destinations outside of Israel will need to go get tested 72 hours prior to the flight.

For inbound travelers, this testing will be acceptable for shortening the required time of quarantine. 

source: Calcalist

I am not sure why this needs to be done in the airport for outbound travelers. They have to go to the airport 72 hours prior to the flight and can't just do it on the way out, going a little earlier. I guess so they don't have to set up multiple labs around the country, though I see a benefit to that as well. It makes sense to have one in the airport for the inbound patients, so everyone leaving Israel will just have to go twice.