In Genesis 21 we are blessed with a very important beginning, the beginning of the nation of Israel. Earlier in scripture, God had promised Abraham a son and now was fulfilling that promise in providing Isaac.
The Old contains the New and the New explains the Old. What that means is that the New Testament can be seen in the Old Testament. In the Old Testament, God makes known predictions, prophecies, and typologies. And, in the revelation of these predictions, prophecies, and typologies,