Sahih Bukhari
Sahih Bukhari Volume 002, Book 022, Hadith Number 299.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 22. Actions While Praying
Narated By Anas bin Malik : We used to pray with the Prophet in scorching heat, and if someone of us could not put his face on the earth (because of the heat) then he would spread his clothes and prostrate over them.