In his letter to the Romans, Paul commends Phoebe to them, “Phoebe, our sister, which is a servant of the church which is at Cenchrea,” and asks them to “receive her in the Lord, as becometh saints, and that ye assist her in whatsoever business she hath need of you; for she hath been a scourer of many and of myself also” (16:1, 2) . Apparently she was paying a business visit to Rome.
It is interesting to note that before he left Corinth with Aquila and Priscilla, Paul had been to Cenchrea and had shorn his head there and had a vow. (Acts 18:19) Cenchrea adjoined Corinth.
On Paul’s having his head shorn, the Cambridge Bible comments, “We can observe all through the narrative of the Acts, that Paul, although the Apostle to the Gentiles, did not cease to regard the festivals and ceremonies of the Jews in things which did not militate against the Christian liberty. For some reason, either during sickness or in the midst of his conflict at Corinth, he had taken a vow upon himself of the nature of the Nazarite vows (Num. 6:1-21). This could only be brought to its fitting close by a journey to Jerusalem to offer up the hair, which it was part of the vow to leave uncut. At Jerusalem, when the ceremony was completed, the head was shaven (see Acts 21:24), but it seems to have been allowed to persons at a distance to cut the hair short, and to bring that (already cut off) with them to the temple and offer it up when the rest was shaven. This appears to be what Paul, did at this time at Cenchrea, before starting on his visit to Syria. The vow was redeemed after thirty days of consecration. This fact explains why Paul could not consent to accept the invitation of the Ephesians to stay with them longer. (Acts 18:20). He had to be in Jerusalem within the limit of thirty days for completion of his vow.
The Origin of the Organic World – Part One