Although I can select 'Hebrew' from: Options->Options...->User interface, after restarting Picard, the actual language remains 'English'.

These are my locale settings:

❯       locale
LANG=he_IL.UTF-8
LANGUAGE=he_IL
LC_CTYPE="he_IL.UTF-8"
LC_NUMERIC=he_IL.UTF-8
LC_TIME=he_IL.UTF-8
LC_COLLATE="he_IL.UTF-8"
LC_MONETARY=he_IL.UTF-8
LC_MESSAGES="he_IL.UTF-8"
LC_PAPER=he_IL.UTF-8
LC_NAME=he_IL.UTF-8
LC_ADDRESS=he_IL.UTF-8
LC_TELEPHONE=he_IL.UTF-8
LC_MEASUREMENT=he_IL.UTF-8
LC_IDENTIFICATION=he_IL.UTF-8
LC_ALL=