The Messenger of Allah ﷺ passed by two graves and said, "These two are being punished, and they are not being punished for something major. As for this one, he did not protect himself from urine. As for this one, he used to walk about spreading slander."Then he called for a fresh palm branch, split it into two pieces, and planted one over this grave and one over that grave. He said, "Perhaps their punishment will be lightened as long as these do not dry out."Hannad said, "Yastatir" in place of "yastanzih."
حدثنا زهير بن حرب وهناد بن السري قالا حدثنا وكيع حدثنا الأعمش قال سمعت مجاهدا يحدث عن طاوس
مر رسول الله ﷺ على قبرين فقال إنهما يعذبان وما يعذبان في كبير أما هذا فكان لا يستنزه من البول وأما هذا فكان يمشي بالنميمة ثم دعا بعسيب رطب فشقه باثنين ثم غرس على هذا واحدا وعلى هذا واحدا وقال لعله يخفف عنهما ما لم ييبسا قال هناد يستتر مكان يستنزه
Bukhari, Etiquette, chapter on backbiting, etc., no. 6052, and Muslim, Purification, chapter on the evidence for the impurity of urine and the obligation to avoid it, no. 292, from the hadith of Waki with this same chain. It was also narrated by Tirmidhi, no. 70, Nasai, no. 31, and Ibn Majah, no. 347.