Musnad Ahmad 33:739

'Abd al-Wahhab narrated to us, Hisham ibn Abi 'Abd Allah informed us, from Abu al-Zubayr, from Jabir ibn 'Abd Allah, that the Prophet of Allah, may Allah bless him and grant him peace, said: "Do not wrap yourselves in the *samma'* (a style of wrapping where the garment is wrapped around the body without leaving an opening for the arms) while in a single garment. And let none of you eat with his left hand. And do not walk in a single sandal. And do not sit in the *ihtiba'* position (sitting with the knees drawn up to the chest) while in a single garment."