Deuteronomy 25:1-2

Young's Literal Translation

25 `When there is a strife between men, and they have come nigh unto the judgment, and they have judged, and declared righteous the righteous, and declared wrong the wrong-doer,

² then it hath come to pass, if the wrong-doer is to be smitten, that the judge hath caused him to fall down, and [one] hath smitten him in his presence, according to the sufficiency of his wrong-doing, by number;