Musnad Abu Ya'la al-Mawsili 155:284

Abu Musa narrated to us, Abd al-Wahhab narrated to us, Muhammad ibn Amr narrated to us, from Abu Salamah, from Abu Hurairah, that the Messenger of Allah (peace and blessings of Allah be upon him) forbade two transactions in one transaction, and two types of clothing, and that a man should sit in the *ihtiba* position (wrapping his arms around his legs while sitting) with nothing between him and the sky, and that one of you should wrap himself in the *samma* garment (a way of wrapping a garment that leaves no opening for the arms) while having it on only one of his shoulders.