Hello Khalaf,
I guess you want the texts to be in Arabic language even in the ENGLISH language logon, right?
If yes try like the below option.
Logon to system in english language.
Goto SE93 --> give F-36 and click on change --> system will ask for a popup, click on the maintain in logon language ---> in the transaction text field give the arabic translation and save.
It worked for me, please check and revert.
Regards,
Thanga