Fatima entered the Kaaba, and then the Holy walls reunited and joined as one.  She stayed in the Kaaba for three days, during which she gave birth to a virtuous baby boy.  The infant was born with his eyes closed and in humble prostration before Allah.  As the fourth day approached, the Kaaba doors reopened and Fatima walked out with her pride and joy in her arms.  Prophet Muhammad (S) was there to greet her and his new cousin.  Women surrounded Fatima anxiously awaiting the name she decided to give to her son.  Fatima told them that while she was inside the Kaaba, she kept hearing a voice say, Name this child Ali.  The name Ali is an optimistic and cheerful name.  It signifies nobility, eminence, and elevation.  No one before Ali (AS) had ever had that name, and no one before him or after him ever had the honor of being born inside the sacred walls of the Holy Kaaba.  The birthplace of Ali (AS) signifies the righteousness within him and that he would one day lead a virtuous and pious life.
 
        A few years after his birth, Ali (AS) had the honorable privilege of moving to and living with the Holy Prophet of Islam, Muhammad (S).  The Prophet (S) asked his uncle, Abu Talib, to allow Ali (AS) to be under his care so he can raise him as if he were his own child.  Ali (AS) grew up with the feeling that Prophet Muhammad (S) and Khadija (AS) were his parents.  As a child, Ali (AS) played with the Prophet's daughter, Fatima (AS), as if she were his sister.
As Ali (AS) was under the care of the Prophet (S), he believed and practiced what the Prophet (S) did.  Ali (AS) received love, education, and guidance firsthand from the Holy Prophet (S) himself.  The Prophet (S) always visited a cave, Hira, in a mountain called Noor.  Ali (AS) had the superb honor of joining the Prophet (S) and his wife (AS).

        An inseparable bond developed between the Prophet (S) and Ali (AS).  Ali (AS) was always at the side of the Prophet (S). Whenever the Prophet (S) went anywhere, Ali (AS) strolled along with him with his little hand grasped in the Prophet's (S) hand.  Whether it was a market or someone's home, Ali (AS) always accompanied the Prophet (S) on all of his visits.  The two were inseparable.  The Prophet (S) has been noted for saying, AI am from Ali, and Ali is from me.  The Prophet (S) considered Ali (AS) to be very unique, but not just for his ability to understand so much at such a young age, but because truth, dignity, and courage illuminated from his young face.  The Prophet (S) new that Ali (AS) would someday have a big influential impact on the progress of Islam.

        Within a few years, Ali (AS) blossomed into a virtually energetic and dynamic ten year old boy.  Even though he was only ten years old, he had a frame of mind of one much older than he.  Ali (AS) was a wise thinker, he had an insurmountable amount of maturity in him that couldn't be found in any child of the same age, and he had a powerful reasoning ability, which was something to behold.

        When Muhammad (S) was declared the Messenger of Allah, Khadija (AS) was the first person to accept the Doctrine of Islam.  As soon as Khadija (AS) performed Shahaada, she and the Prophet began offering prayer.  Ali (AS) walked in and saw his two guardians bowing in worship.  Ali (AS) was so excited at the sight that lay before him.  He thought to himself, could this be a new religion since there wasn't any idols in the room for the Prophet (S) and Khadija (AS) to be worshipping.  When the Prophet (S) and Khadija (AS) finished praying, Ali (AS) asked them who they were bowing to.  The Prophet explained how he had recently become the new Messenger of the Almighty, and that the new and right religion was Islam.

        As Ali (AS) listened carefully, the Prophet (S) asked him if he would join him and Khadija (AS) as Muslims.  Ali (AS) was surprised at the Prophet's (S) question.  However, since he was an unusually wise and mature ten year old boy, Ali (AS) asked to have his father's permission in the matter.  The Prophet (S) granted his request.  That night, Ali (AS) lay in bed with so much excitement.  He pondered upon the question of whether he should ask his father's permission to submit himself to Islam or if he has own personal right to make that choice on his own.  A normal ten year old wouldn't ponder about and stay up half the night thinking about this.  But Ali (AS) was no ordinary boy.  He was gifted with an intellect of someone three times older than him.  The following morning, Ali (AS) quickly jumped out of bed and ran to the Prophet (S).  He happily announced his acceptance of the Divine path of Allah, Tauheed, and that Muhammad (S) was His Messenger.  By that declaration, Ali (AS) became the first male to accept Islam as the Prophet's message. Because Prophet Muhammad (S) had so much faith and trust in Ali (AS), he was the first to hear the new Revelations from the Prophet (S).  This astonishing young boy understood and practiced the word of Islam.  Islam became his life.  It wasn't something that he considered and then applied.  Instead it was something that was rooted in him as he ate, slept, and went about his duties during the day.

        Ali (AS) opened his heart to Islam without asking his father's permission.  Ali (AS) based his decision on a fundamental principle that he came up with at such a young age, which was, AWhile surely Allah didn't consult my father for my creation, Why should I consult my father for my faith!  As young as he was, one can surely see how remarkably intelligent and bright Ali (AS) was.  Prophet Muhammad (S) never asked any other child than Ali(AS) to embrace Islam because his maturity and wisdom was way beyond his present age, and was even above an adult ten times older.

        As Ali (AS) got older, around the age of puberty when young boys experiment new things and become wild, he stayed at the Prophet's (S) side and began defending his honor.  For example, in the battle of Hunain, when the enemy surrounded and seized the Muslims, the Muslims abandoned and left the Prophet (S) behind, as they ran away for their lives.  Ali (AS) was the only one left standing to defend Prophet Muhammad (S).  Ali (AS) saved the Prophet (S) by making the enemies retreat and to take their heals.

        In another battle, Khayber, Ali (AS) not only demonstrated again that he would defend the Prophet's (S) honor, but he also showed his massive courage and strength.  Marhab, a Jewish army soldier known for his immense masculine strength, stood guard at a huge gate called Khyber, which needed forty men to open.  Ali (AS), with one strike of his sword, single-handedly split Marhab in two and opened the gate, which allowed the Muslim army to cross over to the Khayber fort.  This event exemplifies Ali's (AS) willpower and strength to overcome any obstacle that stood in the Prophet's (S) way.

        As Ali (AS) became a man, he was involved in many more events in which he endangered his life for the sake of Allah.  When he was 23 years old, he laid down his life for that of the Prophet (S).  Disbelieving polytheists had plotted to murder the Prophet (S) in his sleep.  Allah hadn't ordered the Prophet (S) to use any physical force, even if it was for self defense.  So He commanded Angel Gabriel (AS) to inform Prophet Muhammad (S) of the plot to kill him.  The Angel (AS) informed the Prophet (S) that Allah has commanded Ali (AS) to lay in the bed of the Prophet (S), while he himself migrates from Mecca to Medina in the darkness of the night.  When Prophet Muhammad (S) told Ali about the events that were to take place, Ali (AS) happily accepted his duty, without an ounce of hesitation.  As he was ordered, Ali (AS) lay in the Prophet's (S) bed at night, with the blanket wrapped over him so the assassins would be tricked into thinking that Ali (AS) was Prophet Muhammad (S).  Yes Ali's (AS) life was at stake. But he didn't care.  He would sacrifice his life for the sake of Islam.  As dawn came around, the would-be assassins entered the Prophet's (S) home, with the intent to kill the Last Messenger of Allah.  The murderers rushed into the Prophet's (S) room.  Just before they were about to carry out the devilish act, one of them, out of curiosity, wanted to pull the covers because he wanted to see the Prophet's (S) look before he was killed.  As he removed the covers, to his surprise and the rest of the murderers with him, he discovered that it wasn't Prophet Muhammad (S).  Instead, it was Ali (S); the cousin of the Prophet (S); the Prophet's (S) right-hand man; the Prophet's (S) savior.  The would-be assassin's were infuriated that there plan had failed.  They screamed at Ali (AS) demanding to know where the Prophet (S) was.  Ali (AS) calmly answered, How do I know, you were the watchers, not I!

        Afterwards, Ali (AS) went about with the rest of his orders, not knowing if the Prophet (S) safely arrived in Medina.  Prophet Muhammad (S) told Ali (AS) to return the jewelry to its owners, which had been entrusted with the Prophet (S) before he left for Medina.  Since he couldn't stay in Mecca because of the threat on his life, Ali (AS) was entrusted with jewelry and to return it to its owners.  Ali (AS) did as he was told.  Then he began his extraneous two-week journey to Medina, to be reunited with Prophet Muhammad (S).  The terrain was rocky, rough, and filled with dangerous thieves and killers.  And by going on foot, Ali (AS) would physically strain himself.  But he didn't care.  All that mattered to him was to be reunited with the Prophet (S) and to make sure that he was out of harms way.  Finally, after two weeks of walking on rough grounds in the unbearable heat, Ali (AS) was reunited with the Prophet (S).  When Ali (AS) arrived, his feet were swollen, blistered, and bruised.  As the Prophet (S) embraced Ali (AS), his heart ached when he saw his beloved cousin's swollen feet.  Prophet Muhammad (S) sat Ali (AS) down and washed his feet, even though Ali (AS) repeatedly objected.  The strong love between the two righteous men of Allah was exemplified in this event.  Ali (AS) was willing to lay down his life for Prophet Muhammad (S), and the Prophet (S) attended to the needs Ali (AS) the way a mother does to her infant child.  Afterwards, Ali (AS) was relieved not that he was still alive, but that the Prophet (S) hadn't been harmed in any way.  What virtuous man, but Ali (AS), would risk his life for someone, come out alive, and only care that that person wasn't killed.

Reference:
FAB (Followers of Ahl-lul Bayt [a.s.] Encyclopedia.