Musannaf Ibn Abi Shayba 28:447

Waki' narrated to us, he said: Sufyan narrated to us, from Habib ibn Abi Thabit, from Abu Wa'il, who said: Umar said: "If I remain, I will surely take the surplus wealth of the rich, and I will surely distribute it among the poor of the Emigrants (Muhajirun)."