Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates: One day the Prophet (peace and blessings be upon him) passed by some graves, and he had a fresh palm branch with him. He split it into two parts, placed one part on one grave and the other part on another grave, then went on. We said: "O Messenger of Allah, why did you do that?" The Prophet (peace and blessings be upon him) said: "One of them was being punished for spreading tales, and the other did not guard himself against urine. As long as this branch remains fresh, the two of them will not be punished."
Al-Tabarani recorded it in al-Mu'jam al-Kabir. Its chain contains Ja'far bin Maysarah, who is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الجنائز / 4293