You will find in today’s reading the only passage I can think of that speaks to an unpardonable sin. We seem to always want to add some sin to this category. The bottom line is that blasphemy towards the Holy Spirit is basically equivalent to rejecting Jesus. If you reject the only way to have sin forgiven, that particular sin is unpardonable.
In chapter 12: 18-21, Jesus quotes Isaiah 42:1–4 relating that he will bring “hope to the Gentiles.” Then he claims that his ministry is only for the Jews (Matt 15:24).
Is this a contradiction? Of course not. One explanation is while Jesus’ focus was on the Jewish Nation to fulfill prophesy, his intention was for the Jews who accepted his teachings to spread the Good News to all nations. That command has been passed to the Gentiles, including us.