It is narrated from Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) that he said: The Messenger of Allah (peace and blessings be upon him) forbade me two prayers, two ways of eating, two kinds of recitation and two ways of dressing. He forbade me to pray after Fajr until the sun has risen high, and after Asr until the sun has set; he forbade me to eat while lying face down on my stomach; and he forbade me to wrap myself in the "samma'" (a sheet wrapped so that the hands cannot come out) and to sit in "ihtiba'" (sitting with the knees drawn up to the stomach) in a single garment when there is no covering between my private parts and the sky. This hadith has a sahih (authentic) chain, but the two Shaykhs (Bukhari and Muslim) did not record it in this form.