Sayyiduna Jabir bin Abdullah (may Allah be pleased with both of them) narrates: We used to perform prayer behind the Prophet Muhammad (peace be upon him) during the intense heat of summer, so one of us would take pebbles in his palm. He would keep them in one hand, then in the other hand, and when they became cool, he would prostrate on them.

Sayyiduna Abdur Rahman bin Shibl Ansari (may Allah be pleased with him) narrates: I heard the Prophet (peace and blessings of Allah be upon him) say: "He forbade three things during prayer: pecking like a crow, spreading the feet like a beast, and that a person designates a specific place for sitting as a camel designates its sitting place."