We have four men - There are with us four men. It is evident that James and the elders meant to say that these men were connected with them in the Christian church; and the fact shows that the Christians at Jerusalem did not disregard the institutions of Moses, and had not been so far enlightened in the doctrines of Christianity as to forsake yet the ceremonial rites of the Jews.
Which have a vow on them - Which have made a vow. See the notes on Acts 18:18. From the mention of shaving the head (in Acts 21:24), it is evident that the vow which they had taken was that of the Nazarite; and that as the time of their vow was about expiring, they were about to be shaven, in accordance with the custom usual on such occasions. See the notes on Acts 18:18. These persons Paul could join, and thus show decisively that he did not intend to undervalue or disparage the laws of Moses when those laws were understood as mere ceremonial observances.