Deuteronomy 19:15

15 One witness shall not stand against any man, whatever thing it is of sin, and of wickedness; but each word shall stand in the mouth of twain, either of three witnesses. (One witness shall not convict anyone, whatever his sin, or wickedness; but each charge must be established by the testimony of two, or three, witnesses.)

Deuteronomy 19:15 Meaning and Commentary

Deuteronomy 19:15

One witness shall not rise up against a man for any iniquity,
or for any sin, in any sin that he sinneth
Whether capital sins, or pecuniary debts; or whatsoever sins a man may be guilty of whether sins against the first or second table of the law, whether greater or lesser sins, whether in moral or civil things; the Jews except only in the case of a woman suspected of adultery and of beheading the heifer:

at the mouth of two witnesses, or at the mouth of three witnesses,
shall the matter be established;
either for acquittance or condemnation; and the witnesses may not, as Jarchi says, write their testimony in a letter, and send it to the sanhedrim, nor may an interpreter stand between the witnesses and the judges; (See Gill on Deuteronomy 17:6).

Deuteronomy 19:15 In-Context

13 and thou shalt not have mercy upon him; and thou shalt do away guilty blood from Israel, that it be well to thee. (and thou shalt not give him any mercy; and so thou shalt do away from Israel the guilt for innocent blood, so that it be well with thee.)

14 Thou shalt not take, and turn over, the terms of thy neighbour, which the former men set in thy possession, which thy Lord God shall give to thee in the land, which land thou shalt take to be wielded. (Thou shalt not take away, or turn over, thy neighbour's boundary stones, which the people in former times put there in thy possession, which the Lord thy God shall give thee, in the land which thou shalt take for thyselves.)

15 One witness shall not stand against any man, whatever thing it is of sin, and of wickedness; but each word shall stand in the mouth of twain, either of three witnesses. (One witness shall not convict anyone, whatever his sin, or wickedness; but each charge must be established by the testimony of two, or three, witnesses.)

16 If a false witness standeth against a man, and accuseth him of breaking of the law,

17 both they, of whom the cause is, shall stand before the Lord, in the sight of priests, and of judges, that be in those days. (then both of the people who be in dispute, shall stand before the Lord, in the sight of the priests, and the judges, who then be in office.)