The story of Daud (David) is best known for his encounter with Goliath the Philistine. The small and young Daud faced the Mighty Goliath with just a sling filled with stones. The references to Daud in the Quran are quite rich.
 Daud's family and Lineage
Daud was one of three sons sent by his father to join the army of King Saul. He married King Sauls daughter Michal (Miqel) after defeating Goliath. They had a son Sulaiman (Solomon), who was also a prophet
 Daud's love of Allah
 Trust in Allah
"When Goliath set eyes on the lean young man who looked like a boy, he laughed loudly and roared: "Are you out to play war with one of your playmates, or are you tired of your life? I will simply cut off your head with one swipe of my sword!"
David shouted back: "You may have armor, shield, and sword, but I face you in the name of Allah, the Lord of the Israelites, Whose laws you have mocked. Today you will see that it is not the sword that kills but the will and power of Allah!" [Ibn Kathirs Stories of the Prophet].
Hebrew Text (Sefer Sh'muel Alef, Perek 17, verse 40): "David said to the Philistine, "You come against me with sword and spear and javelin, but I come against you in the name of the LORD Almighty, the God of the armies of Israel, whom you have defied."
 Fasting for Allah
David (pbuh) fasted every other day. Abdullah Ibn Amr Ibn Al-As narrated: Allah's Apostle (pbuh) said to me: "The most beloved fasting to Allah was the fasting of the Prophet David, who used to fast alternate days. And the most beloved prayer to Allah was the prayer of David, who used to sleep the first half of the night, and pray for one third of it and again sleep for a sixth of it.'" (Sahih Al-Bukhari).
Abdullah Ibn Amr Ibn Al-As also narrated: "The Prophet (pbuh) said to me: 'I have been informed that you pray all the nights and observe fast all the days; is this true?' I replied: 'Yes.' He said: 'If you do so, your eyes will be weak and you will get bored. So fast three days a month, for this will be the fasting of a whole year. (Or equal to the fasting of a whole year).' I said: 'I find myself able to fast more.' He said: 'Then fast like the fasting of (the Prophet) David (pbuh) who used to fast on alternate days and would not flee on facing the enemy.'" (Sahih Al-Bukhari)
 Dauds battle with Goliath
When Goliath set eyes on the lean young man who looked like a boy, he laughed loudly and roared: "Are you out to play war with one of your playmates, or are you tired of your life? I will simply cut off your head with one swipe of my sword!"
David shouted back: "You may have armor, shield, and sword, but I face you in the name of Allah, the Lord of the Israelites, Whose laws you have mocked. Today you will see that it is not the sword that kills but the will and power of Allah!"
So saying, he took his sling and placed in it a pebble from his pouch. He swung and aimed it at Goliath. The pebble shot from the whirling sling with the speed of an arrow and hit Goliath's head with great force. Blood gushed out, and Goliath thumped to the ground, lifeless, before he had a chance to draw his sword. When the rest of his men saw their mighty hero slain, they took to their heels. The Israelites followed in hot pursuit, taking revenge for their years of suffering at the hands of their enemy, killing every soldier they could lay hands on. In this battle the Israelites regained the glory and honor that had been lost for a long time.
 Dauds Kingship
Prophet David was a just and righteous ruler who brought peace and prosperity to his people, and whom Allah honored as a messenger. He delivered Allah's message to the people through the precious gift of his melodious voice. When he recited the Psalms (Zaboor), it was as if the rest of creation chanted with him; people listened as if in a trance. The messages David delivered are famous and well remembered. They are known in the Bible as the Psalms or Songs of David.
David divided his working day into four parts: one to earn a living and to rest, one to pray to his Lord, one to listen to the complaints of his people, and the last part to deliver his sermons. He also appointed deputies to listen to his subjects' complaints so that in his absence people's problems might not be neglected.
Although a king, he did not live on the income of his kingdom. Being well-experienced in the craft of weapon-making, he made and sold weapons and lived on that income.
 Daud's test from Allah
One day, as David was praying in his prayer niche, he ordered his guards not to allow anyone to interrupt him, but two men managed to enter and disturb him. "Who are you?" he asked. One of the men said: "Do not be frightened. We have a dispute and have come for your judgment." David said: "What is it?" The first man said: "This is my brother, has ninety nine sheep, and I have one. He gave it to me but took it back." David, without hearing from the other party said: "He did you wrong by taking the sheep back, and many partners oppress one another, except for those who are believers."
The two men vanished like a cloud, and David realized that they were two angels sent to him to teach him a lesson. He should not have passed a judgment without hearing from the opposing party.
Almighty Allah told us of this incident: And has the news of the litigants reached you? When they climbed over the wall into (his) Mihrab (a praying place or a private room). When they entered in upon David, he was terrified of them, they said: Fear not! (We are) two litigants, one of whom has wronged the other; therefore judge between us with truth, and treat us not with injustice, and guide us to the Right Way."
"Verily, this is my brother (in religion) has ninety nine ewes, while I have only one ewe, and he says: 'Hand it over to me,' and he overpowered me in speech."
David said immediately without listening to the opponent: "He has wronged you in demanding your ewe in addition to his ewes. And, verily, many partners oppress one another, except those who believe and do righteous good deeds, and they are few."
And David guessed that We have tried him and he sought Forgiveness of his Lord, and he fell down prostrate and turned to Allah in repentance. So We forgave him that, and verily, for him is a near access to Us, and as good place of final return Paradise.
O David! Verily! We have placed you as a successor on earth, so judge you between men in truth and justice. And follow not your desire for it will mislead you from the Path of Allah. Verily! Those who wander astray from the Path of Allah shall have a severe torment, because they forgot the Day of Reckoning. (Ch 38:21-26 Quran).
David worshipped Allah, glorified Him and sang His praise until he died. According to traditions, David died suddenly and was mourned by four thousand priests as well as thousands of people. It was so hot that people suffered from the intensity of the sun. Solomon called the birds to protect David and the people from the sun, and they did so until he was buried. This was the first sign of his dominion to be witnessed by the people.