Attab bin Usaid (RAA) narrated that The Messenger of Allah (ﷺ) commanded us, "Grapevines are to be estimated exactly as palm trees, and its Zakah is taken in raisins." Related by the five lmams. (DE)
English reference (DE): Book 4, Hadith 641 (DE)
Arabic reference (DE): Book 4, Hadith 619 (DE)