And sailed thence into Syria - Or set sail for Syria. His design was to go to Jerusalem to the festival which was soon to occur, Acts 18:21.
Having shorn his head - Many interpreters have supposed that this refers to Aquila, and not to Paul. But the connection evidently requires us to understand it of Paul, though the Greek construction does not with certainty determine to which it refers. The Vulgate refers it to Aquila, the Syriac to Paul.
In Cenchrea - Cenchrea was the eastern port of Corinth. A church was formed in that place, Romans 16:1.
For he had a vow - A “vow” is a solemn promise made to God respecting anything. The use of vows is observable throughout the Scripture. Jacob, going into Mesopotamia, vowed one-tenth of his estate, and promised to offer it at Bethel to the honor of God, Genesis 28:22. Moses made many regulations in regard to vows. A man might devote himself or his children to the Lord. He might devote any part of his time or property to his service. The vow they were required sacredly to observe Deuteronomy 23:21-22, except in certain specified cases they were permitted to redeem what had been thus devoted. The most remarkable vow among the Jews was that of the Nazarite, by which a man made a solemn promise to God to abstain from wine, and from all intoxicating liquors, to let the hair grow, not to enter any house polluted by having a dead body in it, or to attend any funeral. This vow generally lasted eight days, sometimes a month, sometimes during a definite period fixed by themselves, and sometimes during their whole lives. When the vow expired, the priest made an offering of a he-lamb for a burnt-offering, a she-lamb for an expiatory sacrifice, and a ram for a peace-offering. The priest then, or some other person, shaved the head of the Nazarite at the door of the tabernacle, and burnt the hair on the fire of the altar. Those who made the vow out of Palestine, and who could not come to the temple when the vow was expired, contented themselves with observing the abstinence required by the Law, and cutting off the hair where they were. This I suppose to have been the case with Paul. His hair he cut off at the expiration of the vow at Cenchrea, though he delayed to perfect the vow by the proper ceremonies until he reached Jerusalem, Acts 21:23-24. Why Paul made this vow, or on what occasion, the sacred historian has not informed us, and conjecture, perhaps, is useless. We may observe, however:
(1) That if was common for the Jews to make such vows to God, as an expression of gratitude or of devotedness to his service, when they had been raised up from sickness, or delivered from danger or calamity. See Josephus, i. 2, 15. Vows of this nature were also made by the Gentiles on occasions of deliverance from any signal calamity (Juvenal, Sat., 12, 81). It is possible that Paul may have made such a vow in consequence of signal deliverance from some of the numerous perils to which he was exposed. But,
(2) There is reason to think that it was mainly with a design to convince the Jews that he did not despise their law, and was not its enemy. See Acts 21:22-24. In accordance with the custom of the nation, and in compliance with a law which was not wrong in itself, he might have made this vow, not for a time-serving purpose, but in order to conciliate them, and to mitigate their anger against the gospel. See 1 Corinthians 9:19-21. But where nothing is recorded, conjecture is useless. Those who wish to see the subject discussed may consult Grotius and Kuinoel in loco; Spencer, De Legibus Hebrae., p. 862; and Calmet’s Dictionary, “Nazarite.”