“Purify yourselves from urine because verily, it is the most common reason for punishment in the grave”

This is a hadith from the 'Explanation of Important Lesson' By Abdul-Aziz bin Abdullah bin BAz....but next to most of the other hadiths, it puts a source, this hadith does not have that, does anyone know the source of it please? Have I made sense? Probably not used the correct terminology...sorry..

JazakAllah in advance!