A (plural: kippot), , skullcap, or is a brimless cap, usually made of cloth, traditionally worn by Jewish males to fulfill the customary requirement that the head be covered. It is worn by all men in Orthodox Jewish communities during prayers and by most Orthodox Jewish men at all other times. Among non-Orthodox Jewish communities, some who wear them do so at all times, while others wear them only during prayer, while attending a synagogue, or in other rituals.
Etymology
The term () literally means "dome" as the kippah is worn on the head like a dome. The term () might be derived from the Polish or the Ukrainian and perhaps ultimately from the Medieval Latin ("cowl" or "hood"). It may also be of Turkic origin (akin to , meaning "rainwear"). The word is often associated with the phrase (), formed from the Aramaic word for 'king' and the Hebrew root , meaning 'fear'. or is another Yiddish term for the same thing.
Jewish law
Halachic authorities debate as to whether wearing a at all times is required. According to Maimonides, Jewish law dictates that a man is required to cover his head during prayer.
In non-Orthodox communities, some women also wear , and people have different customs about when to wear a when eating, praying, studying Jewish texts, or entering a sacred space such as a synagogue or cemetery. The Reform movement has historically been opposed to wearing , but wearing a kippah during Torah study and/or prayer has become common and accepted among Reform men and women.
According to several prominent authorities, however, the practice has since taken on the force of law because it is an expression of ("reverence for Heaven"; i.e., respect for God). The 17th-century authority David HaLevi Segal holds that the reason is to enforce the Halachic rule to avoid practices unique to non-Jews. Segal reasons that, as Europeans are accustomed to going bareheaded, and their priests insist on officiating with bare heads, this constitutes a uniquely non-Jewish practice. Therefore, he posits, that Jews should be prohibited from behaving similarly and rules that wearing a is required by Halacha.
Other Halachic authorities, like the Sephardi posek Chaim Yosef David Azulai, hold that wearing a head covering is a —an additional measure of piety. In a recent responsum, former Sephardic Chief Rabbi of Israel Ovadia Yosef ruled that it should be worn to show affiliation with the religiously observant community.
The Talmud states, "Cover your head in order that the fear of heaven may be upon you." Rabbi Hunah ben Joshua never walked four cubits () with his head uncovered, saying "because the Divine Presence is always over my head." This was understood by Rabbi Yosef Karo in the Shulchan Arukh as indicating that Jewish men should cover their heads and should not walk more than four cubits bareheaded. Covering one's head, such as by wearing a , is described as "honoring God". The modifies this ruling by adding that the Achronim established a requirement to wear a head covering even when traversing fewer than four cubits, and even when one is standing still, indoors and outside. Kitzur Shulchan Aruch cites a story from the Talmud (tractate Shabbat 156b) about Rav Nachman bar Yitzchak, who might have become a thief had his mother not saved him from this fate by insisting that he cover his head, which instilled in him the fear of God. In Orthodox communities, boys are encouraged to wear a from a young age in order to ingrain the habit.
The Talmud implies that unmarried men did not wear a :
The Tanakh implies that covering one's head is a sign of mourning:
The argument for the has two sides. The Vilna Gaon said one can make a without a , since wearing a is only a ("exemplary attribute"). In the 21st century, there has been an effort to suppress earlier sources that practiced this leniency, including erasing lenient responsa from newly published books. Or Zarua (13th century) wrote that "our rabbis in France" customarily made blessings while bareheaded, but he criticized this practice.
According to 20th-century Rabbi Isaac Klein, a male Conservative Jew ought to cover his head when in the synagogue, at prayer or sacred study, when engaging in a ritual act, and when eating. In the mid-19th century, Reformers led by Isaac Wise completely rejected the after an altercation in which Rabbi Wise's was knocked off his head. Nowadays, almost all Conservative synagogues require men to wear a head covering (usually a ), but in Reform synagogues there is no requirement. However, may be provided to anybody who wishes to wear them.