He said that unless it was due to sexual immorality, the one who divorced his wife and married another would be committing adultery.
Virtually everyone was shocked to hear what Jesus was saying.
I disagree that this limits our Lord's words to the engagement period, and not beyond.
Our Lord's questioners responded by asking why Moses commanded that one give his wife a bill or certificate of divorce.
Jesus made it very clear that Moses never commanded divorce; he permitted it because of the hardness of men's hearts (Matthew 19:7-8). In a sinful, fallen, world, divorce is a pragmatic way of dealing with broken relationships.
I disagree with those who attempt to take this text further than what Jesus has said.
They tell us that Jesus meant for this to apply only during the betrothal period, before the marriage was consummated.
It seems to me that those who hold to this highly restrictive view fail to remember the purpose of divorce.
Divorce was permitted because of man's sin; it was a protection for the innocent party.
Whether one can remarry, then, is determined by whether or not the divorce itself was biblical.
A divorce on biblical grounds constitutes the right to remarry, in my opinion.
They had made the exception (there can be divorce, when there is sexual immorality) to be the rule (there can be divorce for any reason at all).
Divorce was so rampant that Jesus wanted them to see that God was not permissive about divorce.
I would remind you that this is a parallel passage to Matthew 19.