you're getting confused because there are too many replies in this thread which imply you can enable Hebrew notifications & keep the band's menus in English, without flashing a custom firmware - that is simply WRONG.
I'm assuming you're using Android:
1. Install latest official Mi Fit version to make sure your band is updated to fw 2.0.0.4 & current resources
2. Flash custom English fw
Firmware 2.0.0.4 | English Bold Font | Xiaomi Mi Band 3 | GeekDoing
3. Change band language in Notify & Fitness (latest version) to Arabic
4. Uninstall Mi Fit - if you want to keep RTL notifications