Khalid bin Duraik (may Allah have mercy on him) said: I asked Ibn Muhayriz (may Allah have mercy on him): "May food and animal fodder be sold in the land of the Romans?" He said: I heard Sayyiduna Fadalah bin Ubayd (may Allah be pleased with him) say: "Some people want to make me slip from my religion. That will not happen until death comes to me and I meet Muhammad (peace and blessings be upon him) and his companions. Whoever sells, for gold or silver, food or fodder that he obtained in the land of the Romans, in it is the one-fifth of Allah and the fay' of the Muslims."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 18000
Sayyiduna Fadalah bin Ubayd (may Allah be pleased with him) said: "Some people want to turn me away from my religion, and by Allah, I hope to remain upon it until I die. Anything that is sold for gold or silver, in it is the one-fifth of Allah and the share of the Muslims."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 18001
Hani' bin Kulthum (may Allah have mercy on him) said: After the conquest of Syria, the commander of the army wrote to Umar (may Allah be pleased with him): "We have conquered a land abundant in food and animal fodder. I do not want to take any step without your order, so write instructions to us." So Sayyiduna Umar (may Allah be pleased with him) wrote: "Do not stop the people from eating and obtaining fodder, and whatever is sold for gold or silver, in it is the one-fifth and the share of the Muslims."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 18002