The Messenger of Allah ﷺ said, "Most of the punishment of the grave is due to urine."
حدثنا أبو بكر بن أبي شيبة حدثنا عفان حدثنا أبو عوانة عن الأعمش عن أبي صالح
قال رسول الله ﷺ أكثر عذاب القبر من البول
[Hasan] Ahmad reported it in 2/388 from Affan, with the same wording, and it is also in Musannaf Ibn Abu Shayba, 1/122. Hakim and Dhahabi graded it sahih, as did Busiri.Amash used an ambiguous form of transmission (anana), as noted earlier, no. 178, and it has a hasan corroborating narration in Nasai, no. 1344.