27 When the seven days were almost completed, the Jews from Asia, who had seen him in the temple, stirred up the whole crowd. They seized him, 28 shouting, "Fellow Israelites, help! This is the man who is teaching everyone everywhere against our people, our law, and this place; more than that, he has actually brought Greeks into the temple and has defiled this holy place." 29 For they had previously seen Trophimus the Ephesian with him in the city, and they supposed that Paul had brought him into the temple. 30 Then all the city was aroused, and the people rushed together. They seized Paul and dragged him out of the temple, and immediately the doors were shut. 31 While they were trying to kill him, word came to the tribune of the cohort that all Jerusalem was in an uproar.
Matthew Henry's Commentary on Acts 21:27-31
Commentary on Acts 21:27-40
(Read Acts 21:27-40)
In the temple, where Paul should have been protected as in a place of safety, he was violently set upon. They falsely charged him with ill doctrine and ill practice against the Mosaic ceremonies. It is no new thing for those who mean honestly and act regularly, to have things laid to their charge which they know not and never thought of. It is common for the wise and good to have that charged against them by malicious people, with which they thought to have obliged them. God often makes those a protection to his people, who have no affection to them, but only have compassion for sufferers, and regard to the public peace. And here see what false, mistaken notions of good people and good ministers, many run away with. But God seasonably interposes for the safety of his servants, from wicked and unreasonable men; and gives them opportunities to speak for themselves, to plead for the Redeemer, and to spread abroad his glorious gospel.