Soon after his birth the Prophet (S.A.W) took Ali (A.S.) under his care and his wife Khadija adopted him as her own son. Ali (A.S.) lived with them. He was fed, washed, dressed by the Prophet (S.A.W) himself. The Prophet (S.A.W) made him sleep in his own bed, and took him wherever he went.

Ali (A.S.) describing his upbringing by the Prophet (S.A.W) says,
"I was still a new born baby when the Prophet took me from my parents. I used to cling to him and was attached to him like a baby camel attached to its mother. To me he was like a guiding star. I used to carefully follow his actions and deeds. He used to put before me the high values of morality and advised me to follow them. Every year the Prophet used to spend some days at Mount Hera (a desert hill near Mecca) and I used to be with him. I was his only companion and none else could meet him there".

The constant company of the Prophet (S.A.W) gave Ali (A.S.) the opportunity to absorb all the attributes of the Prophet (S.A.W)’s character in the matter of knowledge, self sacrifice, forbearance, bravery, kindness, generosity, oratory and eloquence. What others heard from the Prophet (S.A.W) he too heard but what he heard from the Prophet (S.A.W) when was alone with him, the others did not hear.

It is a well known fact that every tradition Ali (A.S.) narrated was that he heard from the Prophet (S.A.W) himself. When somebody questioned him as to why he is being preferred on others in the matter of knowledge and traditions, Ali (A.S.) replied, "The Prophet replied to what I asked and he told me what I did not ask". Speaking about the Prophet (S.A.W), Ali (A.S.) said, "He is the leader of all who exercise fear (of Allah) and light for them who seek guidance. He is a lamp, whose flame is burning, a meteor whose light is shining and flint whose spark is bright. His conduct is upright, his behaviour is guiding, his speech is decisive and his decision is just."