Musnad Ahmad 33:750

Ahmad ibn Abd al-Malik narrated to us, Muhammad ibn Salamah narrated to us, from Muhammad ibn Ishaq, from Muhammad ibn Yahya ibn Habban, from his paternal uncle Wasi’ ibn Habban, from Jabir ibn Abdullah, who said: "The Messenger of Allah, peace and blessings of Allah be upon him, commanded that from every harvest of dates, ten wasqs be given, with a cluster hung in the mosque for the poor."