Musannaf Ibn Abi Shayba 3:819

Abu Bakr narrated to us, he said: Abd al-A’la narrated to us, from Ma’mar, from al-Zuhri, from Salim, from Ibn Umar, that Umar ibn al-Khattab saw a man praying while wrapped [in a single garment]. He said: "Do not resemble the Jews. Whoever among you does not find anything but a single garment, let him wrap it around his waist."