By the mouth of two or three witnesses, he who is to be put to death shall perish. Let no one be killed with only one person speaking testimony against him
Other versions
King James Version
At the mouth of two witnesses, or three witnesses, shall he that is worthy of death be put to death; but at the mouth of one witness he shall not be put to death.English Standard Version
On the evidence of two witnesses or of three witnesses the one who is to die shall be put to death; a person shall not be put to death on the evidence of one witness.New International Version
On the testimony of two or three witnesses a man shall be put to death, but no one shall be put to death on the testimony of only one witness.