Almighty Allah declared: So they routed them by Allah 's Leave and David killed Goliath, and Allah gave him (David) the kingdom after the death of Saul and Samuel and wisdom, and taught him of that which He willed. And if Allah did not check one set of people by means of another, the earth would indeed be full of mischief But Allah is full of Bounty to the Alamin (mankind, jinns and all that exist)." Surah 2: 251
Related Quran Ayaaths of this Hadith.
Surah 6 : Ayah 84 Surah 4 : Ayah 163 Surah 11 : Ayah 25 Surah 11 : Ayah 32 Surah 11 : Ayah 36 Surah 17 : Ayah 55 Surah 27 : Ayah 15 Surah 27 : Ayah 16"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