Mishkat al-Masabih
Mishkat al-Masabih 338
وَعَنِ ابْنِ عَبَّاسٍ قَالَ مَرَّ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ بِقَبْرَيْنِ فَقَالَ إِنَّهُمَا لَيُعَذَّبَانِ وَمَا يُعَذَّبَانِ فِي كَبِيرٍ أَمَّا أَحدهمَا فَكَانَ لَا يَسْتَتِرُ مِنَ الْبَوْلِ - وَفِي رِوَايَةٍ لمُسلم: لَا يستنزه مِنَ الْبَوْلِ - وَأَمَّا الْآخَرُ فَكَانَ يَمْشِي بِالنَّمِيمَةِ ثمَّ أَخذ جَرِيدَة رطبَة فَشَقهَا نِصْفَيْنِ ثُمَّ غَرَزَ فِي كُلِّ قَبْرٍ وَاحِدَةً قَالُوا يَا رَسُول الله لم صنعت هَذَا قَالَ لَعَلَّه يُخَفف عَنْهُمَا مَا لم ييبسا
Ibn ʿAbbās reported that the Prophet passed by two graves and said: ‘Their occupants are being punished, though they are not being punished for something considered great. One of them did not protect himself from urine’—in a version transmitted by Muslim: ‘did not cleanse himself thoroughly from urine’—‘and the other used to spread malicious gossip.’ He then took a fresh palm frond, split it in two, and planted one piece on each grave. They asked: ‘Messenger of God, why did you do that?’ He replied: ‘Perhaps their punishment will be lightened as long as these remain moist.’
Translation notes
The accompanying grading labels this report muttafaq ʿalayh (‘agreed upon’). The source gives two wordings for the first person’s failing: not shielding himself from urine, and, in Muslim’s version, not cleansing himself thoroughly.