Whoever has wealth on which zakaah must be paid does not have to pay it from the stored wealth itself, rather he can pay it from other wealth.
Al-Nawawi (may Allaah have mercy on him) narrated in al-Majmoo’ (5/346) that the scholars were unanimously agreed that it is permissible to pay zakaah from wealth other than the wealth on which it is due.
And Allaah knows best.