Acts 20:3

‘And when he had spent three months there, and a plot was laid against him by Jews as he was about to set sail for Syria, he determined to return through Macedonia.'

The three months of continual ministry in Corinth having come to an end Paul now determined to set sail directly for Syria on a ‘pilgrim boat' with other Jews and Jewish Christians who were going to Jerusalem to attend the Feast of Pentecost, but he learned of plots laid against him by Jews as he was about to set sail which made him change his mind. It was far to easy for someone to ‘disappear' on a boat journey. So he determined rather to return through Macedonia. The hatred and determination of the Jews to destroy this one man are an indication of the widespread impact of his ministry, and of the sinfulness and hardness of the hearts of some ‘dedicated' Jews.

At this time of the approaching Feast of Pentecost many Jews would be taking ship for Caesarea and Jerusalem, and thus any ship could be a place of danger, for some had clearly determined to take the opportunity of getting rid of Paul, probably at sea. We may presume that a ‘brother' or a rare friendly Jew was able to warn him of the danger. The threat of Jerusalem hung over him even there.