This is a parable found exclusively in the Gospel of Matthew. It is not clear whether this parable existed independently as a parable or whether it was conceived as an allegory from the beginning. Those who think that the parable existed independently interpret the parable to mean a statement against building of boundaries and so excluding some. The building of boundaries and forming exclusive communities is not the business of human beings, but is God’s task.
Like the field in the parable there is good seed and there are weeds even in the world in which we live. There is both good and evil. We are called to take only what is good and not focus too much on the evil or bad. This does not mean passivity in the face of evil but a call for a discerning mind and heart.