It is narrated from Abu Sa'id Khudri (may Allah be pleased with him) that the Messenger of Allah (ﷺ) said: "There is no zakat on less than five camels."
Hadith Referenceمسند الإمام الشافعي / كتاب الزكاة / 703
Hadith Takhrijأخرجه البخارى الزكاة، باب ليس فيما دون خمس ذوي صدقة (1459)۔