Majma al-Zawaid — Hadith 13135

Sayyiduna Abu Bakrah (may Allah be pleased with him) narrates: Once I was walking along with the Prophet (peace and blessings be upon him), and he was holding my hand, and another man was on his left. Two graves came before us, and the Prophet (peace and blessings be upon him) said: "These two are being punished, and they are not being punished for something (apparently) major (that is, a major sin that is difficult to avoid)." Then he said: "Yes indeed (it is major): one of them did not guard himself against his urine, and the other used to go about spreading tale-bearing. Which of you will bring me a branch?" The narrator says: The two of us raced, and I got there before my companion and brought the branch. The Prophet (peace and blessings be upon him) split it into two halves, placed one piece on one grave and the other piece on the other grave, and said: "As long as these two remain fresh, their punishment will be lightened; and these two are being punished only for backbiting and for (not guarding against the splashes of) urine."
(Allamah al-Haythami says:) I say: Imam Ibn Majah has recorded part of this narration.
This narration was recorded by Imam Ahmad, and its narrators are the narrators of the Sahih, except for Bahr bin Marrar, and he is thiqah (trustworthy).