Deuteronomy 25:3-5

Complete Jewish Bible

³ but the maximum number is forty. He is not to exceed this; if he goes over this limit and beats him more than this, your brother will be humiliated before your eyes.

⁴ “You are not to muzzle an ox when it is treading out the grain.

⁵ “If brothers live together, and one of them dies childless, his widow is not to marry someone unrelated to him; her husband’s brother is to go to her and perform the duty of a brother-in-law by marrying her.