Why did God send Hagar back to Abraham and Sarah's tent before the child was born?
God sent Hagar back to Abraham and Sarah's tent before the child was born so that she would have to go through the same thing thirteen years later, and so that we could have a New Testament lesson. This is presented as a parallel to Peter, whom God prepared through prior experience for a later defense of Paul's ministry.
Les explains that God sent Hagar back to Abraham and Sarah's tent before the child was born so that she would have to endure the same trial thirteen years later. The stated reason is so that we could have a New Testament lesson. Les compares this to Peter, whom God had providentially prepared by sending him to Cornelius's house twelve years earlier. When the Acts 15 council arose, God reminded Peter of that earlier Gentile salvation so Peter could defend Paul's position. Thus the larger purpose was not only Cornelius's salvation but preparing Peter for that later defense.