Thank you so much, my dear friend, for this very interesting question. First, let me quote verses 2-7, then we can consider the background of such “vows”. Leviticus 27:2-7 reads: “Speak unto the children of Israel, and say unto them, When a man shall make a singular vow, the persons shall be for the LORD by thy estimation. And thy estimation shall be of the male from twenty years old even unto sixty years old, even thy estimation shall be fifty shekels of silver, after the shekel of the sanctuary. And if it be a female, then thy estimation shall be thirty shekels. And if it be from five years old even unto twenty years old, then thy estimation shall be of the male twenty shekels, and for the female ten shekels. And if it be from a month old even unto five years old, then thy estimation shall be of the male five shekels of silver, and for the female thy estimation shall be three shekels of silver. And if it be from sixty years old and above; if it be a male, then thy estimation shall be fifteen shekels, and for the female ten shekels”.

My understanding of the vows, as related to Old Testament Jewish law, is that vows were never required of the children of Israel by the Jewish laws or traditions; however, if a vow of consecration of a person, or some animal or piece of property was made by an individual, then before God, the person making the vow was obliged to keep the vow. Generally, the thing vowed was given to the priest; but if the priest didn’t want it, then there was a monetary exchange which is spelled out in this chapter. I believe that the MacDonald Commentary on Leviticus 27 gives a very nice explanation of this particular situation: “The last chapter of Leviticus deals with voluntary vows made to the Lord. It seems that in gratitude to the Lord for some blessing, a man could vow to the Lord a person (himself or a member of his family), an animal, a house, or a field. The things vowed were given to the priests (Numbers 18:14). Since these gifts were not always of use to the priests, provision was made that the person making the vow could give the priest a sum of money in lieu of the thing vowed…”. Thus, I believe that the above sums up what an Israelite must do if he did elect to enter into a vow of consecration for any reason.

However, I feel that I must clarify here that vows were not required of anyone. It is important to understand that Christians would not make such vows; and even if this were done, there would be no such requirements according to the law of Moses. Christians, whether of Jewish or Gentile birth come to the Lord on the ground of faith only, and not on the grounds of keeping the Old Testament law (Romans 6:14; Acts 10:9-15, and 28; Acts 11:17, 18; Acts 15:5-29; Ephesians 2:8,9; Titus 3:5). Now, we do read that the Apostle Paul did apparently make a vow (Acts 18:18); and similarly, in Acts 21:17-26, we do see Paul with four Jewish Christians shaving their heads in some type of vow, possibly a Nazarite vow. These are the only two examples of vows that I am aware of in the New Testament. In Acts 21:17-26 we might get some insight into how these things came to be. Paul had gone to Jerusalem, and he met with the church there to report on his activities in the Gospel. It was reported to him there that there were many Jews who were “jealous” for the law, and these were apparently concerned about Paul’s teaching (verses 20-21). It appears to me that the church in Jerusalem wanted to avoid trouble with the Jews regarding Paul’s teachings. And so, in verses 23-26 we read the counsel that was given to Paul there: “Do therefore this that we say to thee: We have four men which have a vow on them; Them take, and purify thyself with them, and be at charges with them, that they may shave their heads: and all may know that those things, whereof they were informed concerning thee, are nothing; but that thou thyself also walkest orderly, and keepest the law. As touching the Gentiles which believe, we have written and concluded that they observe no such thing, save only that they keep themselves from things offered to idols, and from blood, and from strangled, and from fornication. Then Paul took the men, and the next day purifying himself with them entered into the temple, to signify the accomplishment of the days of purification, until that an offering should be offered for every one of them”. Now, I will not pretend to know what Paul’s thinking was in following this request in taking on this vow. In the first century church, there were many Jewish believers, and there were also “Judaizers” who tried to preach adding some of the law, especially circumcision, to salvation. It could be that there were some Jewish Christians in Jerusalem who were trying to convince Paul to participate in this so as not to cause a great stir among the Jews in Jerusalem. Paul did comply with this request, but the Jews were stirred up in any case. Now, we do know that Paul never taught Christians to return to the law as this would add another requirement for salvation, and in fact he taught quite the contrary. In Galatians 2:16, we clearly see what Paul believed and taught regarding the true Gospel of Jesus Christ: “Knowing that a man is not justified by the works of the law, but by the faith of Jesus Christ, even we have believed in Jesus Christ, that we might be justified by the faith of Christ, and not by the works of the law: for by the works of the law shall no flesh be justified”. Thus we read Paul’s words in Galatians 2:11-14:”But when Peter was come to Antioch, I withstood him to the face, because he was to be blamed. For before that certain came from James, he did eat with the Gentiles: but when they were come, he withdrew and separated himself, fearing them which were of the circumcision. And the other Jews dissembled likewise with him; insomuch that Barnabas also was carried away with their dissimulation”.

So, in summary to your question, what you are seeing in Leviticus 27 is merely a recording of what the Old Testament Jew needed to do in order to fulfill their requirements before the law in case any did make a vow of consecration, and also the options they had in the law in the event that the Israelite making such a vow had the need of paying the monetary value of any person or property so consecrated. None of this would apply to Christians today, whether Jew or Gentile.  (SF)  (521.4)