Q: The Torah specifies that children disrespectful of their parents be put to death. How did the rabbis deal with this?
A. Rabbis of the Talmudic period were reluctant to carry out the punishment of crimes of one insulting or beating one's parents (Shemot 21:15,17). In fact, the Talmud calls a court that executes a criminal even once in 7 years "a wicked Sanhedrin [court]" (Makkot 1:10). And, R' Eliezer ben Azariah said that such a court deserves that appellation if it executes a criminal even once in 70 years. R' Akiva, a 1st century scholar, and R' Tarphon, a 2nd century scholar, opposed capital punishment under all circumstances. R' Simeon ben Gamaliel, president of the Sanhedrin in the 2nd century, disagreed, saying that not to execute a criminal guilty of a capital offense encourages criminal activity.
This was no light matter to the Rabbis... when they would be called to impose the death penalty upon a criminal they would fast on the day that they would sentence the person to death. (Sanhedrin 63a).An interesting study is Shemot 21:15 which concludes with the words mot yumat "that man shall surely be put to death." Since the word for death is repeated in the Hebrew phrase (both mot and yumat are forms of the word for death), the Rabbis concluded that this was intended to teach that the death penalty is to be imposed only by G-d, not by man. For, when the Scriptures wishes to indicate death at the hands of a human tribunal (as in Shemot 35:3), the word mot is used alone.