The Prophet ﷺ said, "Wealth is not measured by abundance of possessions, but true wealth is the richness of the soul."
حدثنا عمر بن أيوب الموصلي عن جعفر عن يزيد
عن النبي ﷺ قال ليس الغنى عن كثرة العرض ولكن الغنى غنى النفس
Its isnad is sahih. Umar bin Ayub Mawsili Abdi is trustworthy and reliable according to Ibn Main, Abu Dawud, and others, and he has already been mentioned at 10900.