It is narrated from Sayyiduna Zayd bin Thabit (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "O Zayd! Pay the zakah for your head (that is, for your own person) along with the people, even if you find nothing but a single sa' of wheat."
Hadith Referenceالمعجم الكبير للطبراني / باب الزاي / 4789