Abu Hurairah (May Allah be pleased with him) said:
The Messenger of Allah ﷺ said, "It is much better for one of you to sit on a live coal, which will burn his clothes and get to his skin than to sit on a grave."

[Muslim].

عن أبي هريرة رضي الله عنه قال: قال رسول الله ﷺ :" لأن يجلس أحدكم على جمرة، فتحرق ثيابه، فتخلص على جلده خير له من أن يجلس على قبر" ((رواه مسلم))