It is reported by Jabir bin Abdullah (ra) that they had accompanied the messenger of Allah when they came to two graves. Both the inmate of the graves were being punished. He said," They are being punished not for committing a grave sin. But, yes! (They are grave sins though on the face of it they are ordinary and it is easy to avoid them but their punishment is severe.) One of them was given to backbite other people while the other was not. Careful to clean himself of urine drops (over his body)". He then asked for one or two branches of fresh date palm and split them and dug them on each grave. He said afterwards," Soon their punishment will be softened as long as the branches are green." Or he said, “Until they dry up.”  

كُنَّا مَعَ رَسُولِ اللهِ ﷺ فَأَتَى عَلَى قَبْرَيْنِ يُعَذَّبُ صَاحِبَاهُمَا فَقَالَ إِنَّهُمَا لاَ يُعَذَّبَانِ فِي كَبِيرٍ وَبَلَى أَمَّا أَحَدُهُمَا فَكَانَ يَغْتَابُ النَّاسَ وَأَمَّا الْآخَرُ فَكَانَ لاَ يَتَأَذَّى مِنَ الْبَوْلِ فَدَعَا بِجَرِيدَةٍ رَطْبَةٍ أَوْ بِجَرِيدَتَيْنِ فَكَسَرَهُمَا ثُمَّ أَمَرَ بِكُلِّ كِسْرَةٍ فَغُرِسَتْ عَلَى قَبْرٍ فَقَالَ رَسُولُ اللهِ ﷺ أَمَا إِنَّهُ سَيُهَوَّنُ مِنْ عَذَابِهِمَا مَا كَانَتَا رَطْبَتَيْنِ أَوْ لَمْ تَيْبَسَا  

It is reported by Qays that Amr bin al-Aas (ra) was going somewhere with his friends. They saw a dead mule whose belly had swollen up. Amr (ra)said," By Allah, it is better for one to eat to his full from this (dead mule) than to eat the flesh of a Muslim" (He meant to say that to backbite anyone is worse than eating the meat of a dead animal).  

لَأَنْ يَأْكُلَ أَحَدُكُمْ هَذَا حَتَّى يَمْلَأَ بَطْنَهُ خَيْرٌ مِنْ أَنْ يَأْكُلَ لَحْمَ مُسْلِمٍ