Introduction Mishnah four discusses a person who through one act incurs two different types of death penalty.
While in the previous mishnah we learned that if we are unsure of which death penalty a person is to receive he gets the more lenient one, in our mishnah we learn that if a person deserves two death penalties, he gets the more severe one.
He who incurs two death penalties imposed by the court is executed by the severer. Section one deals with a person who has committed two different crimes which carry the death penalty. Even if he was already sentenced to the lighter death penalty, and then committed another crime which carries a more severe form of the death penalty, he still gets the more severe form. In other words, we do not say that since he already was sentenced to one death penalty it is as if he has already been executed and therefore he cannot get another.
If he committed one sin for which a twofold death penalty is incurred, he is executed by the severer. R. Jose says: “He is judged according to the first penalty which was placed upon him.” Section two deals with a person who through one crime receives two different forms of the death penalty. For instance if a man has relations with his married mother-in-law he is obligated for burning (since he had relations with a mother and her daughter) and for strangulation, since he committed adultery. According to the Sages he again receives the more serious form of the death penalty. According to Rabbi Yose he receives the death penalty for the crime which potentially existed first. We will explain. If he marries a widow’s daughter, this woman is now forbidden to him since she is his mother-in-law but she is not forbidden as a married woman, since she is a widow. If he were to now have relations with her he would be punished through burning. If she were then to get married, the punishment would also be strangulation. Since the prohibition of a mother-in-law existed first, he is punished by burning. If, however, she was married and then he married her daughter, he would be punished by strangulation, since she was first prohibited to him due to her being a married woman.