Hi mohamad.ali.jalali37,
Thank you for your asking. Please follow the steps below:
Setting>System>Languages & input>Languages>Add a language,
go to the last 20% position and you will see Farsi. No hesitate to contact me if you have any other question.
If you still cannot find it we suggest that you update to WW-16.2017.2004.063 and check again.
How to update firmware:
https://www.asus.com/support/FAQ/1009748/ZB602KL Firmware Download Spot:
https://www.asus.com/Phone/ZenFone-Max-Pro-M1/HelpDesk_BIOS/