Jesus says these words in answer to his disciples who asked him why he speaks in parables. He explains that not everyone is given to know the mysteries of the kingdom of heaven, but only people who are open, only those who accept his words and live them.
In fact, some of those who hear him choose to close their eyes and ears so that “they look but do not see and hear but do not listen or understand” (Mt. 13:13). These are people who see and hear Jesus, but because they assume that they already know all the truth, they do not believe his words or the actions that confirm them. For this reason, they end up losing even the little they have.