Musannaf Ibn Abi Shayba 28:804

Waki’ narrated to us, he said: Ibn ‘Awn narrated to us, from Khalid ibn al-Durayk, from Ibn Muhayriz, from Fadalah ibn ‘Ubayd al-Ansari, who said: "Indeed, a people want to cause me to slip away from my religion. But by Allah, I hope to die while I am upon it. Whatever there is of gold or silver, then in it is the fifth for Allah and the shares of the Muslims."