Musnad Ahmad 31:903

'Abd al-Razzaq narrated to us, he said: Ma'mar narrated to us, from al-Zuhri, from 'Ata' ibn Yazid al-Laythi, from Abu Sa'id al-Khudri, who said: "The Messenger of Allah (may Allah bless him and grant him peace) forbade two types of clothing and two types of sales. As for the two types of clothing: 'Ishtimal al-Samma' (the wrapping of the deaf), which is for a person to wrap himself in a single garment, placing both ends of the garment upon his left shoulder, leaving his right side exposed; and the other is to sit in a squatting position (ihtiba') in a single garment, with nothing else on him, such that his private parts are exposed to the sky. As for the two types of sales: al-Munabadhah and al-Mulamasah. Al-Munabadhah is for him to say: 'When I throw this garment to you, the sale has become binding.' And al-Mulamasah is for him to touch it with his hand without wearing it or turning it over, and if he touches it, the sale becomes binding."