Lesser Penalties (Leviticus 20:19-21).
Three examples are now given of slightly lesser crimes, still forbidden but not punishable with death.
“And you shall not uncover the nakedness of your mother's sister, nor of your father's sister, for he has made naked his near kin. They shall bear their iniquity.”
Men must not have sexual relations with aunts or uncles of the blood whether in marriage or out of marriage. That will be to make naked their near kin, and that is displeasing to God. In that case they must receive whatever punishment the courts or God decide.
“And if a man shall lie with his uncle's wife, he has uncovered his uncle's nakedness. They shall bear their sin. They shall die childless.”
For a man to have sexual relations with his uncle's wife is unseemly, for she is one flesh with his uncle. They are not to marry. This too may be judged by the courts, but they are also warned that they will go childless.
“And if a man shall take his brother's wife, it is impurity. He has uncovered his brother's nakedness. They shall be childless.”
For a man to take his brother's wife is impurity. It is unseemly. He will have uncovered his brother's nakedness and exposed his brother to shame. The punishment will be childlessness. But this was not to stop him from raising up seed to his brother under a levirate marriage. That would be a different matter. The consummation was then probably more discreetly arranged.