Abu Imran al-Jawni says that Sayyiduna Abu Bakr (may Allah be pleased with him) sent Yazid bin Abi Sufyan (may Allah be pleased with him) towards Syria. He mentioned the hadith, at the end of which is: "Slaughter camels and cows only for food."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 18132