Studying the verses of the Qur'an and noting the great and important deeds that Abraham (a.s.) fulfilled and, hence, being appointed to the position of Imamat by Allah, leads us to the conclusion that the term / kalimat / meaning ' words ', or the divine commandments by which Abraham (a.s.) was tried, were not those of the usual sort. it clearly indicates that the tests were not connected with matters of ordinary reasoning or faith. they can never be considered ordinary tests. the purpose of the ' words ' was a series of heavy, hard, laborious, grave duties which were given to Abraham, the sincere pure prophet (a.s.), and he was the only one who had the qualifications to successfully complete them. some of those commandments were such as the followings :
One trial was concerning the steadfastness of his faith in Allah. Abraham (a.s.) was commanded through a vision in a dream to slay his son ishmael. when he awoke, he unhesitatingly acted as he was bidden, (37: 105-108). this indicates that Abraham (a.s.) already knew that he was Allah's prophet and what he saw in the vision was no other than Allah's command. with such a certainty in his mind, he was willing to do, by Allah's command, something that no other loving or sensible father possibly could slay his own son.
In another incident, by Allah's command, he took and left his wife and his infant son to an area of dry land, where no food and water or any inhabitants could be found.
He also stood against the idol-worshippers of babylon and very bravely defended monotheism in his historical trial after he had broken their idols. he miraculously held firm in faith and patience when he was thrown into the midst of fire.
Recalcitrating, he emigrated from the land of idol-worshippers, and went to a faraway region in order to proclaim his prophecy. he did many things similar to those mentioned above and each of those trials was, indeed, heavy and difficult for a man to undertake, but he, with the power of faith, was able to perform them successfully thereby proving himself worthy of the position of ' Imamat ', divine leadership.
source : http://www.maaref-foundation.com