 Hosein Nasr states that non-Islamic origin theories are false according to the point of view of Sufism.Many have asserted Sufism to be unique within the confines of the Islamic religion, and contend that Sufism developed from people like Bayazid Bastami, who, in his utmost reverence to the sunnah, refused to eat a watermelon because he did not find any proof that Muhammad ever ate it.According to William Chittick Sufism can simply be described as "the interiorization, and intensification of Islamic faith and practice."