Abu al-Hasan al-Ridha عليه السلام said: A man from among the companions of Ali عليه السلام called Qays was praying, after he finished the first unit a large black snake came and crawled onto the place of prostration, when he [Qays] lowered his forehead near it the snake latched onto his neck, encircled it and left slithering through his inner garment [but he did not break his prayer]! I [the Imam] was returning one day from al-Fur` [a place between Makka and Madina] when the time of prayer entered. I dismounted and proceeded near a Thumama [panic grass] shrub. When I completed a single unit a snake came near me, but I continued with my prayer and did not shorten it in any way nor did I allow any deficiencies to come into it. It came near me then returned to the shrub. Only when I had completed my prayer and followed it up by my normal supplication did I call the one who was with me and said: Keep away from the snake under the shrub. Whoever fears none except Allah then He suffices for him.