Why didn't God reveal to Avraham the identity of the mountain upon which he was instructed to bind his son? How did Avraham know the location?
God commands Avraham to travel to the land of Moriah, and to bring his beloved son Yitzchak as a burnt-offering "on one of the mountains, of which I will tell you." However, the explicit identity of the mountain is not even mentioned once in the entire episode!
Avraham gets up early in the morning, and departs with his son Yitzchak and his servants "and went to the place of which God had told him" – to the land of Moriah. On the third day, Avraham lifted up his eyes "and saw the place from afar." How did Avraham know that this was the place, if God hadn't told him specifically which mountain He meant? Where in the text did God tell Avraham what his destination will be? And why did God hide the information as to the location of the mountain from Avraham in the first place?
A possible explanation is that, as far as God is concerned, the very fact that Avraham was prepared to go to the land of Moriah, was in itself a test. God deliberately did not name a specific mountain, so that Avraham would not take any action prior to a second revelation in which God would tell Avraham that he had successfully withstood the trial. This revelation would have been the end of the trial and then it would not have been necessary to bind Yitzchak to the altar.
However, love distorts the natural order, and Avraham hastened to fulfill God's command as soon as reached the land of Moriah. He was of the opinion that God's initial command included offering his son as a burnt offering. He was afraid that a delay in this act because he did not know the exact location would then be considered running away from his obligation. Therefore Avraham bound Yitzchak to the altar on one of the mountains, thus proving, above and beyond what was expected of him, his absolute faith in God.
We can now understand the deeper significance of the name given at the end of the story to this mountain – "God will see" (Gen. 22:14)