Why did Air India 139 fly so far south?
(flightaware.com) Return flight.

AI 140 (the return flight) arrives closer to the Pakistani FIR border. The south route when flying westward can be explained by jet stream avoidance.

Apart from the recent exceptions given to Air India by Saudi Arabia and Oman, the countries shown below do not permit flights to enter their airspace if their destination/origin is Israel (flightservicebureau.org, March 2018).

This is also briefly covered on FR24's blog.