I dunno, which flag would serve as a comprehensible shorthand for Arabic? How many Arabic readers would recognise that flag? How many Spanish speakers would recognise the Spanish flag?
If you use flags I would still recommend putting the language name in the language next to it, for example the French flag next to 'Français'.
If you use flags I would still recommend putting the language name in the language next to it, for example the French flag next to 'Français'.