Deuteronomy 25:3 in the King James Version
Forty stripes he may give him, and not exceed: lest, if he should exceed, and beat him above these with many stripes, then thy brother should seem vile unto thee.
Context
2 It shall be, if the wicked man is worthy to be beaten, that the judge shall cause him to lie down and to be beaten before his face, according to his wickedness, by number.
3 He may sentence him to no more than forty stripes. He shall not give more, lest if he should give more and beat him more than that many stripes, then your brother will be degraded in your sight.
4 You shall not muzzle the ox when he treads out the grain.