The Gemara in Masechet Shabbat (106) discusses the prohibition of "Tzad," trapping animals, which is included among the thirty-nine categories of forbidden activity on Shabbat. A number of different cases are addressed in the Gemara, such as hunting birds, deer and grasshoppers.
Does this prohibition apply as well to trapping human beings?
The Gemara establishes a rule limiting the prohibition of "Tzad" to the category of "She'be'mino Nitzod" species that are commonly hunted. Deer, for example, is a special of animals that people frequently hunt, and so trapping a deer transgresses this prohibition. Ants, by contrast, are not normally hunted, and thus trapping ants does not violate the Torah prohibition of "Tzad." The question thus becomes whether human beings qualify for classification as "She'be'mino Nitzod," a species whose members are commonly captured.
Some authorities argued that since human beings are taken captive and imprisoned during warfare, we do, indeed, consider a person a creature that is commonly "hunted," and thus capturing a human being would transgress the prohibition of "Tzad." The Avnei Neizer (Rabbi Avraham Borenstein of Sochatchev, Poland, 1839-1910), however, disagreed with this position, and distinguished between adults and children. Children, he held, are frequently restrained, and thus "trapping" a child would indeed constitute "Tzad." Adults, by contrast, are not normally restrained, and thus one would not violate this prohibition by capturing an adult human being.
In light of these approaches, we might ask whether a parent may punish a child on Shabbat by locking him in his room. Since, as we have seen, "Tzad" applies to restraining children, and possible adults, as well, does one violate the Torah prohibition of "Tzad" by locking a child in his room?
The Gemara establishes that a person who locks an animal in a pen on Shabbat does not violate the prohibition of "Tzad" if he could easily restrain that animal in a single lunge. An animal that could be so easily captured essentially lives in an existential condition of "captivity." Hence, locking it in a confined area does not constitute an act of trapping, given that the animal is already deemed "trapped." Several authorities extend this principle to children, whom a parent can generally restrain quite easily. They thus live at all times in a condition of "captivity," and locking a child in one's room thus does not transgress the prohibition of "Tzad."
Summary: Some authorities maintain that the prohibition against trapping animals on Shabbat applies even to human beings, whereas others distinguish between adults and children, claiming that only capturing children would violate this prohibition. Nevertheless, locking a child in a room is not forbidden on Shabbat, since a parent can in any event easily restrain the child.
