Hi,
It's Turkish. That's why your palestinian said it's farsi and iranian friend said it's arabic
The first inscription is simply the owner's name: Ahmed
The second one is: Elde bıçak gerek dilde sübhan-which can be roughly translated as "One should have sword(knife) in his hands and the Subhan (popular name for Sorat Al-Isra from Quran) in his tongue."
I could only read the third and fourth inscriptions partially, I will try to give it more thought.
Best,