Paul left Ephesus and now heads to Jerusalem.
Commentators see a parallel between our Lord Jesus and Paul. Both do a final journey to Jerusalem (see Luke 9:22,44; 18::31-34 and compare with Acts 20:22-24; 21:4; 21:10-11) where suffering is expected by the hands of Jews.
This section from Acts 21:17-23:35 (covering less than 12 days ) marks the end of Paul's 3rd missionary journey and the beginning of his imprisonment.
We also see the tension between God's guidance and human decision-making in light of warnings given by others. We also see how in Christ the community of faith is bound in fellowship. These are important for us today as well. It will raise questions about our commitment to the service of Christ and to the fellowship of the saints.