It appears that since the beginning of time, physical beauty has been a factor in the attraction between men and women. This attraction caused Cain to envy his brother Abel. He rebelled against Allah's command by refusing to accept his father's advice.
At first glance Cain's rebellion might appear strange, but we should remember that, although man has a pure nature, the potential for dichotomy exists. In other words, he has both good and bad qualities. He can become greedy, covetous, possessive, selfish and even destructive. Man is, therefore, capable of seeking self-satisfaction even if it leads to failure in this life and in the hereafter. The path to goodness lies in harnessing the enemy within him, his baser self, by controlling evil thoughts and deeds and practicing moderation in his desires and actions. His reward then will be the delights of this world and the hereafter. Thus Allah tests us through our divided nature.
Related Quran Ayaaths of this Hadith.
Surah 2 : Ayah 31 Surah 2 : Ayah 33 Surah 2 : Ayah 34 Surah 2 : Ayah 35 Surah 2 : Ayah 37 Surah 7 : Ayah 11 Surah 7 : Ayah 19 Surah 7 : Ayah 26 Surah 7 : Ayah 27 Surah 7 : Ayah 31 Surah 7 : Ayah 35 Surah 3 : Ayah 33 Surah 3 : Ayah 59 Surah 5 : Ayah 27"When a person dies, his works end, except for three: ongoing charity, knowledge that is benefited from, and a righteous child who prays for him."
Prophet Mohammed (PBUH)
"The best of what a man leaves behind are three: a righteous child who supplicates for him, ongoing charity the reward of which reaches him, and knowledge that is acted upon after him."
Sunan Ibn Mājah
"Every day two angels come down from Heaven and one of them says, 'O Allah! Compensate every person who spends in Your Cause,' and the other (angel) says, 'O Allah! Destroy every miser.'"
Sahih Bukhari