Deuteronomy 19:15

15 One witness is not enough to accuse a person of a crime or sin. A case must be proved by 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 Show no mercy. You must remove from Israel the guilt of murdering innocent people so that things will go well for you.
14 Do not move the stone that marks the border of your neighbor's land, which people long ago set in place. It marks what you inherit in the land the Lord your God is giving you as your own.
15 One witness is not enough to accuse a person of a crime or sin. A case must be proved by two or three witnesses.
16 If a witness lies and accuses a person of a crime,
17 the two people who are arguing must stand in the presence of the Lord before the priests and judges who are on duty.
Scripture taken from the New Century Version. Copyright © 1987, 1988, 1991 by Thomas Nelson, Inc. Used by permission. All rights reserved.