Deuteronomy 19:15

15 "A single witness shall not prevail against a man for any crime or for any wrong in connection with any offense that he has committed; only on the evidence of two witnesses, or of three witnesses, shall a charge be sustained.

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 Your eye shall not pity him, but you shall purge the guilt of innocent blood from Israel, so that it may be well with you.

14 "In the inheritance which you will hold in the land that the LORD your God gives you to possess, you shall not remove your neighbor's landmark, which the men of old have set.

15 "A single witness shall not prevail against a man for any crime or for any wrong in connection with any offense that he has committed; only on the evidence of two witnesses, or of three witnesses, shall a charge be sustained.

16 If a malicious witness rises against any man to accuse him of wrongdoing,

17 then both parties to the dispute shall appear before the LORD, before the priests and the judges who are in office in those days;