Genesis Bible Study CH 21 & 22

Chapter 21: Well the long awaited promise arrives!!! At the age of 90, which sounds old to us but in Bible times was not old considering people lived 300 years or more, Sarah have birth to a son. I am sure Isaac brought such joy to their hearts...they had waited SOOOO long for him. Sarah catches Ishmael, Isaac's 1/2 brother, mocking Isaac and demands that Ishmael and his mother be banished....Abraham allowed it.
After being sent away they almost died of thirst, then the Lord provided them water. He, the Lord, promised to make Ishmael into a great nation. (Just as he had promised to make Isaac into a great nation.)

Chapter 22: Verse 2 is striking to me as a parent.......Then God said, "Take your son, your only son, Isaac, whom you love, and go to the region of Moriah. Sacrifice him there as a burnt offering on one of the mountains I will tell you about." Genesis 22:2
I just can't even imagine being asked to do such a thing after waiting a life time to have a child. I understand God was testing Abraham's faith, but I don't think I would have been able to obey like Abraham. I also am struck by Abraham's immediate obedience as a response to what God was calling him to do. I think that is so key in our walk with Lord. We demand immediate obedience from our children, so why wouldn't our Heavenly Father expect it from His children.
This whole situation ends well in verse 11-12: But the angel of the Lord called out to him from heaven, Abraham! Abraham!" "Here I am," he replied. "Do not lay a hand on the boy," he said. "Do not do anything to him. Now I know that you fear God, because you have not withheld from me your son, your only son." What great reminder to us how God rewards us when we obey him which such a willing heart.