When God first spoke to Avraham to issue the command of Akeidat Yitzhak, Avraham replied, “Hineini” (“Here I am” – 22:1).
Commenting on this word, Rav Avraham ben Ha-Rambam notes the distinction between Avraham’s response and that of Adam, when God spoke to him in Gan Eden after he partook of the forbidden tree. Avraham lived in a state of preparedness, ready to receive and obey God’s word; Adam, however, was caught off guard, and was frightened upon hearing God’s voice.