Musannaf Ibn Abi Shayba 3:2712

Muhammad ibn Abi ‘Adi narrated to us, from Ibn ‘Awn, who said: Muhammad [ibn Sirin] used to be asked about a man who gathers [zakat/charity] from these *mazalif* (outlying areas/pastures). He would say: "The Ansar used to gather from the *mazalif* around Medina."