how to create a mask in Hebrew?

[Snoopy]

it turns out that if I set the mask to all the characters, then the hashcat should match in any language or I did not understand you correctly, I mean the encoding
for example - pass > אב
?a?a?a?a must find

in fact no.

take a look at the HEX representation of the ASCII-Table https://www.asciitable.com/, as you can see there is no CHAR/SIGN in ASCII representing in D7 (the starting point in UTF-8 for most(all?, didnt checked) hebrew letters

so there will never be a combination of your desired HEX-Values when using ?a?a?a?a, you could use ?b?b?b?b instead, but this will test all possible HEX-values, this is the point 

take a look https://www.utf8-chartable.de/unicode-utf8-table.pl from U+0590 (hebrew), there you cans see the hex representation of the chars, plain chars (no accents or similar) all starts with D7, so take a look at  Banaanhangwagen's answer