Zakat (Kitab Al-Zakat)
Dawud :: Book 9 : Hadith 1599
Narrated Attab ibn Usayd:
The Apostle of Allah (peace_be_upon_him) commanded to estimate vines (for collecting zakat) as palm-trees are estimated. The zakat is to be paid in raisins as the zakat on palm trees is paid in dried dates.