Musnad Ahmad 33:653

Hujayn and Yunus narrated to us, they said: Layth narrated to us—Yunus said—from Abu al-Zubayr, from Jabir ibn Abdullah, from the Messenger of Allah (peace and blessings of Allah be upon him), that he forbade *ishtimal al-samma’* (wrapping oneself in a garment such that no exit is left for the arms), and *al-ihtiba’* (sitting with the knees drawn up to the chest) while wearing a single garment, and that a man should raise one of his legs over the other while he is lying on his back.