صحیح ابن حبان
Ibn Hibban
كتاب الصلاة
Book of Prayer
باب ما يكره للمصلي وما لا يكره - ذكر الإباحة للمصلي تبريد الحصى بيده للسجود عليه عند شدة الحر
Chapter on What is Disliked and Not Disliked – Permissibility to Cool Pebbles for Prostration in Extreme Heat
2 hadith
Hadith 2276
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.
Hadith 2277
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."