Hadithcore
Mishkat al-Masabih, 1011

Jabir said, “I used to pray the noon prayer with God’s Messenger, and would take a handful of pebbles to cool them in my palm and lay them down to put my forehead on them when prostrating myself because of the excessive heat.” Abu Dawud transmitted it, and Nasa’i transmitted something similar.

وَعَنْ جَابِرِ قَالَ: كُنْتُ أُصَلِّي الظُّهْرَ مَعَ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فآخذ قَبْضَة من الْحَصَى لتبرد فِي كفي ن أَضَعُهَا لِجَبْهَتِي أَسْجُدُ عَلَيْهَا لِشِدَّةِ الْحَرِّ. رَوَاهُ أَبُو دَاوُد وروى النَّسَائِيّ نَحوه

References1 variant
In-Book Reference
Book 4, Hadith 430