Sufyan bin Wahb (may Allah be pleased with him) said: Amr (may Allah be pleased with him) said: I will not say anything about it until I write to Umar bin al-Khattab (may Allah be pleased with him). Amr (may Allah be pleased with him) wrote to Umar (may Allah be pleased with him), and Umar (may Allah be pleased with him) replied.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قسم الفيء والغنيمة / 12829