(93) CHAPTER. To offer As-Salat (the prayer) using an Anaza (a spear-headed stick) (as a Sutra).
Narrated Anas Ibn Malik: Whenever the Prophet went for answering the call of nature, I and another boy used to go after him with a staff, a stick or a short spear (or stick) and a tumbler of water and when he finished from answering the call of nature we would hand that tumbler of water to him.
Authentic