Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "There is no zakah on less than five uqiyah of silver, there is no zakah on less than five wasq of dates, and there is no zakah on less than five camels either."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7421