He was endowed with spiritual understanding from an early age. Allah enlightened his heart and mind and gave him wisdom from childhood. Allah the Almighty stated: And indeed We bestowed aforetime on Abraham his (portion of) guidance, and We were Well-Acquainted with him (as to his Belief in the Oneness of Allah, etc.). Surah 21: 51
During his early childhood Abraham realized that his father made strange statues. One day, he asked him about what it was he made. His father replied that he made statues of gods. Abraham was astonished and he spontaneously rejected the idea. Being a child, he played with such statues, sitting on their backs as people sit on the backs of donkeys and mules.
One day, his father saw him riding the statue of Mardukh and he became furious. He ordered his son not to play with it again.
Abraham asked: "What is this statue, father? It has big ears, bigger than ours."
His father answered: "It is Mardukh, the god of gods, son! These big ears show his deep knowledge."
This made Abraham laugh. He was only seven years old at that time.