"Now it came to pass, that when we had departed from them and set sail, running a straight course we came to Cos, the following day to Rhodes, and from there to Patara. And finding a ship sailing over to Phoenicia, we went aboard and set sail. When we had sighted Cyprus, we passed it on the left, sailed to Syria, and landed at Tyre; for there the ship was to unload her cargo. And finding disciples, we stayed there seven days. They told Paul through the Spirit not to go up to Jerusalem. When we had come to the end of those days, we departed and went on our way; and they all accompanied us, with wives and children, till we were out of the city. And we knelt down on the shore and prayed. When we had taken our leave of one another, we boarded the ship, and they returned home. And when we had finished our voyage from Tyre, we came to Ptolemais, greeted the brethren, and stayed with them one day" (Acts 21:1-7).
After he finished speaking to the Ephesian elders, Paul left Miletus by ship. Their goal is to make it back to Jerusalem by Pentecost. They continue traveling south and east by ship, making various stops along the way. After leaving Patara, they sail around Cyprus to its south (which was the most direct course to Tyre).
Paul and his traveling companions spend a week in Tyre. They are now fairly close to Jerusalem, and they know precisely how much time it would take to make it to Jerusalem before Pentecost (even if they had to walk the rest of the way). They find a group of disciples in Tyre and choose to spend a week with these brethren, no doubt doing their best to strengthen them in the faith.
Although there is no indication that they had known Paul previously or were close to him, these brethren warned Paul not to go to Jerusalem. They knew--to some degree--that bad things were going to befall Paul in Jerusalem. What was the source of this knowledge? The Holy Spirit! They were evidently able to prophesy in regards to this matter. It would seem that Paul, with all the power God had granted to him, could not predict his own future. This is consistent with the truth illustrated elsewhere that those who wielded God's power could not use such directly for their own personal benefit (e.g., healing oneself or prophesying in regards to one's own future). Let it be understood that although these disciples, by means of the Holy Spirit, may have learned about persecution that Paul would face in Jerusalem, it seems they took it upon themselves to try to persuade Paul not to go up. If the Spirit had not wanted Paul to go to Jerusalem, He could have easily communicated such directly (e.g., Acts 16:6,7). The knowledge was supernatural, but the advice given here was the result of human judgment.
As we have explained before, Paul felt compelled to go to Jerusalem for both evangelistic and benevolent purposes. It did not matter what his enemies did to him; it did not matter how much he suffered. He was going to continue serving God to the best of his ability! He would not be moved from his plans (cf. Acts 20:24). What an example for us today (cf. I Cor. 11:1)!
Even in the span of a week, a strong bond is formed between these Christians and Paul. The families that made up the congregation in Tyre accompanied Paul to the shore, where they all prayed together. The journey to Jerusalem then continued.