Hadith 6:978
Yahya ibn Sa’id narrated to us, from Muhammad ibn Abi Yahya, from his father, who said: I used to follow Abu Hurayrah to funerals, and he would judge [the status of] the graves. He said: "That one of you should sit upon a burning coal, so that it burns his clothes, then his shirt, then his lower garment, until it reaches his skin, is more beloved to me than that he should sit upon a grave."
حدثنا يحيى بن سعيد عن محمد بن أبي يحيى عن أبيه قال كنت أتبع أبا هريرة في الجنائز فكان يقضي القبور قال لأن يجلس أحدكم على جمرة فتحرق ثيابه ثم قميصه ثم ازاره حتى تخلص إلى جلده أحب إلي من أن يجلس على قبر