With regard to the student who is devoting all his time to seeking shar’i knowledge, even if he is able to earn a living, it is permissible to give him zakaah, because seeking shar’i knowledge is a type of jihad for the sake of Allaah, and Allaah has made jihad for the sake of Allaah one of the categories on which zakaah may be spent. Allaah says (interpretation of the meaning):
“As-Sadaqaat (here it means Zakaah) are only for the Fuqaraa’ (poor), and Al‑Masaakeen (the poor) and those employed to collect (the funds); and to attract the hearts of those who have been inclined (towards Islam); and to free the captives; and for those in debt; and for Allaah’s Cause (i.e. for Mujaahidoon — those fighting in a holy battle), and for the wayfarer (a traveller who is cut off from everything); a duty imposed by Allaah. And Allaah is All-Knower, All-Wise” [al-Tawbah 9:60]
But if the student is devoting all his time to seeking worldly knowledge, then he should not be given zakaah. We say to him: now you are striving for worldly gain, and you could acquire worldly gains by working, so we should not give you zakaah.