Acts 21:29
( For they had seen before with him in the city Trophimus an Ephesian, whom they supposed that Paul had brought into the temple.) ( For they had seen before with him in the city Trophimus an Ephesian, whom they supposed that Paul had brought into the temple.)
People had previously seen Paul in the city in company with Trophimus, an Ephesian. On that basis they supposed that Paul had brought Trophimus with him into the temple, but this was only supposition and was mistaken, for Paul had not done so. Paul's own entry into the temple was no violation of the law, since as a Jew he had the right to enter there.
The false claim that he had brought a Gentile inside was taken up to underlay and support the charge that he had profaned the holy place. That accusation stirred the crowd to anger against Paul. It issued in an uproar in which Paul was seized and his life was put in danger. The account continues with Paul addressing the crowd from the stairs and beginning his defense in the Hebrew tongue.