Charles Ellicott Commentary Leviticus 27:29

"No one devoted, that shall be devoted from among men, shall be ransomed; he shall surely be put to death." — Leviticus 27:29 (ASV)

None devoted, who shall be devoted from among men. —Better, Every one banned, who shall be banned from among men, that is, everyone banned from among men, or every human being banned, is not to be redeemed. Like the cattle and the patrimonial estates, once devoted to God by a vow of banning, the man thus banned by a vow comes irretrievably under the class of “most holy to the Lord,” or one irrevocably withdrawn from the power of man.

But shall surely be put to death. —Not as a sacrifice to God, but, on the contrary, to be removed from His sight. This is the apparent import of the passage and seems to be confirmed by the melancholy narrative of Jephthah and his daughter (Judges 11:30).

This seems to have been the interpretation given to the law in question during the Second Temple period, since it is embodied in the Chaldee Versions, which render the verse as follows: “Every vow that shall be vowed concerning a man shall not be redeemed with money, but with burnt offerings and with hallowed victims, and with supplications for mercy before the Lord, because such are to be put to death.” It is, however, supposed that this awful vow of banning could only be exercised on notorious wrongdoers and idolaters who were dangerous to the faith of the Israelites, that it could not be made by any private individual on his own responsibility, and that when such cases occurred the community or the Sanhedrin carried out the ban as an act of judicial necessity, thus showing it to be “most holy to the Lord.” Accordingly, Leviticus 27:28–29 address two different cases.

The former regulates objects “banned to the Lord,” which differs from the vow of dedication discussed in Leviticus 27:2-8 only insofar as it is unredeemable, while Leviticus 27:29 regulates the banning enacted by the law itself (Exodus 22:19), or pronounced by the court of justice on a man who is irretrievably to be put to death.