question #1 Sahih al-Bukhari 1361, Book 23, Hadith 114 : What actions can lead to punishment in the grave according to Islamic teachings?

The Prophet (ﷺ) once passed by two graves, and those two persons (in the graves) were being tortured. He
said, “They are being tortured not for a great thing (to avoid). One of them never saved himself from
being soiled with his urine, while the other went about committing slander (to make enmity between
friends). He then took a green leaf of a date-palm tree split it into two pieces and fixed one on each
grave. The people said, “O Allah’s Messenger (ﷺ)! Why have you done so?” He replied, “I hope that their
punishment may be lessened till they (the leaf) become dry.”