Deuteronomy 25:2-4

Young's Literal Translation

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;

³ forty [times] he doth smite him -- he is not adding, lest, he is adding to smite him above these -- many stripes, and thy brother is lightly esteemed in thine eyes.

⁴ `Thou dost not muzzle an ox in its threshing.