Quran: Man's Selfishness

Man is by nature unstable; when misfortune touches him he panics
and when good things come his way, he prevents them form reaching others. [Quran: 70: 19-21]

Men's personalities have been permeated with greed [or selfishness]. [Quran: 4: 128]

The successful are those who can be saved from their own selfishness. [Quran: 59:9, 64: 16]

Say [O Muhammad! to these pagans]: If you were to possess the entire treasures of my Lord's mercy and munificence,
you would still sit over them out of fear of spending [on others] and man is, indeed niggardly! [Quran: 17:100]