Abu Bakra reported,

While I was walking alongside the Messenger of Allah ﷺ, he was holding my hand, with another man on his left side, when we came upon two graves in front of us.The Messenger of Allah ﷺ said, "These two are being punished, and they are not being punished for something great. Yes indeed. Which of you will bring me a palm branch?"We raced off, and I outran him, then I brought him a palm branch. He broke it into two halves, placed one piece on this grave and one piece on that grave, and said, "It will lighten their punishment as long as the pieces remain moist. They are only being punished for urine and backbiting."

Azami 3850

Hasan

عن أبي بكرة قال

بينما أنا أماشي رسول الله ﷺ وهو آخذ بيدي، ورجل عن يساره فإذا نحن بقبرين أمامنا، فقال رسول الله ﷺ: إنهما ليعذبان، وما يعذبان في كبير، وبلى، فأيكم يأتيني بجريدة؟ فاستبقنا، فسبقته، فأتيته بجريدة فكسرها نصفين، ألقي على ذا القبر قطعة، وعلى ذا القبر، قطعة، وقال: إنه يهون عليهما ما كانا رطبتين، وما يعدبان إلا في البول والغيبة.

الأعظمي 3850حسن
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Funerals
Chapter
Conditions of the deceased in the grave
Section
Most of the punishment of the grave is due to urine and tale-bearing
Numbering
Jami al-Kamil 3850 (2nd edition)