عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ رَضِيَ اللَّهُ عَنْهُ عَنْ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ أَنَّهُ قَالَ: ”يَأْكُلُ التُّرَابُ كُلَّ شَيْءٍ مِنَ الْإِنْسَانِ إِلَّا عَجْبَ ذَنَبِهِ“، قِيلَ: وَمِثْلُ مَا هُوَ يَا رَسُولَ اللَّهِ؟ قَالَ: ”مِثْلُ حَبَّةِ خَرْدَلٍ مِنْهُ تَنْبُتُونَ“
It is narrated from Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: The earth consumes the entire body of a human except for the last part of the tailbone. Someone asked: What is its size? He (peace and blessings be upon him) said: Like a mustard seed; you will be resurrected from it.