In the verses before MT 22:14 it says that a king sent people to oversee his vineyard. And each time they were murdered. This was a reference to the prophets in the old testiment who were rejected by the Jews.
From this it might be said in the following parable about the garment, that few are chosen means that only a few of these people will be chosen for the christian church. And as history proves, some did join the christian church, but most did not.
The spiritual interpretation of this could mean that those clothed in sanctifying grace, the life of God within the soul, will be the ones admitted to heaven and the rest rejected.
May the Lord bless you.