The English term “brother-in-law” can denote one of four possible familial connections: A woman’s husband’s brother, a woman’s sister’s husband, a man’s wife’s brother, and a man’s sister’s husband. In this essay we explore the words for the sibling of one’s spouse and the spouse of one’s sibling in the Hebrew language. Our point of departure is the commandment of the Levirate Marriage, which decrees that when a childless married man dies, then one of the deceased’s brothers must marry his widowed sister-in-law (Deut. 25:5). The phrase Levirate Marriage is derived from the Latin word levir (“brother-in-law”). The Hebrew term for this commandment is yibbum — a cognate of the words yavam/yevamah, used to describe the deceased’s brother (yavam) and the deceased’s widow (yevamah) who are commanded to marry each other.
Rabbi Shlomo Pappenheim of Breslau (1740-1814) offers a fascinating etymological explanation of the term yavam. He traces it to the biliteral root BET-MEM, whose core meaning is reflected in the word bam (“in them/through them”). As Rabbi Pappenheim clarifies, this two-letter root can be further broken down into a merger of two single monoliteral roots, the letter BET (the prefix “in/through”) and the letter MEM (the suffix “them”). Rabbi Pappenheim thus understands the root BET-MEM to denote the conglomeration and meeting point of multiple parties. As such, he explains that the Hebrew word bamah (“private altar”) is derived from this word, as it denotes a site at which many people gathered in communal worship. Bamah also denotes “high place” — and many commentators even understand this to be the word’s original meaning — because such gatherings typically happened at elevated places to increase their visibility.
When it comes to the word yavam, Rabbi Pappenheim explains that this term for a relative-in-law stands in stark contrast to other terms for relatives-in-law. For example, in any given marriage, a spouse will only have one father-in-law and one mother-in-law, so the terms that denote those sorts of kinship (choten/chotenet or cham/chamot) are always limited to one person. By contrast, through marrying one’s spouse, a bride or groom can accrue any number of siblings-in-law. This has the potential to create a sort of “mass gathering” of family members. Hence the word for a sibling-in-law (yavam/yevamah) is derived from the root that denotes the meeting and conglomeration of multiple individuals.
Rabbi Yaakov Tzvi Mecklenburg (1785-1865) cites Rabbi Pappenheim’s explanation, but ultimately prefers a different approach. He too connects the word yibbum to bamah but explains the connection differently. He adopts the traditional understanding of the word bamah as a “high place,” and thus explains that yibbum entails “lifting up” a downtrodden and childless widow by marrying her and making her feel important again. Alternatively, he suggests that yibbum involves “elevating” the deceased brother’s soul by establishing a family in his name.
Based on the Talmudic principle that one and one’s spouse are considered the same, Rabbi Pappenheim broadens the definition of yavam/yevamah to even include one’s spouse’s sibling’s spouse. To that effect he cites Ruth 1:15, in which Naomi characterizes Orpah as Ruth’s yevamah even though she was Ruth’s husband’s brother’s wife. (This usage is also found in the Mishna in Yevamot 15:4, where yevamah refers to a woman’s husband’s brother’s wife.)
Rabbi Pappenheim further explains that the act of the Levirate Marriage is called yibbum because when the deceased’s brother died, his wife was no longer actively considered a sister-in-law to his brothers; yet when one of the dead brother’s brothers marries her, she rejoins the family and is now once again considered a sister-in-law to the remaining brothers. Because marrying the widow entails reintroducing her as a yevamah to the rest of the family, the commandment to marry her is called yibbum.
Rabbi Wolf Heidenheim (1757-1832) takes the exact opposite approach, explaining that the verb yibum does not imply reinstating the widow’s lost status as a yevamah, especially because from a halachic perspective she always remains a sister-in-law to her husband’s brothers. Rather, yibum implies one brother marrying her and making her his wife instead of a yevamah, andthus effectivelyeliminating her status as a yevamah vis-à-vis himself. Rabbi Heidenheim thus compares the relationship between the noun yevamah and the verb yibbum to the noun shoresh (“root”) and the verb l’sharesh, which means “to uproot.” According to this approach, the act of yibbum serves to undo her status as yevamah and instead make her a wife.
Alternatively, Ibn Ezra (to Gen. 38:8) seems to explain that the term yibbum does not relate to the yevamah, but to the yavam. The act of yibbum is then the quintessential act of “brother-in-lawing” one’s yevamah in the sense that the yavam responsibly acts in the way of brothers-in-law who take charge of their widowed sisters-in-law and bring them into their own family (see also Meshech Chachmah to Deut. 25:5).
Rabbi Mecklenberg and others (cited by Rabbi Heidenheim) explain that Biblical Hebrew has no special word for “brother-in-law” or “sister-in-law.” Rather, the latter is called eshet achiv (literally, “his brother’s wife”) like in Gen. 38:8-9, Lev. 18:16, 20:21, and it is only in later Rabbinic Hebrew that the terms giss/gissa* for siblings-in-law were introduced. They argue that the terms yavam/yevamah refer specifically to those who are party to the commandment of yibbum and are not general kinship terms for siblings-in-law. Nonetheless, Rabbi Heidenheim cites Ibn Ezra (mentioned above) and HaBachur (below), who clearly disagree with this approach and understand yavam/yevamah to have a kinship meaning even outside of the context of yibbum.
Rabbi Heidenheim further argues that the term giss refers exclusively to one’s spouse’s sibling (or their spouse), such that two men are gissim only if they married two sisters. With this explanation, Rabbi Heidenheim argues that one’s sister’s husband is not called a giss, even though in English we would call him a “brother-in-law.” Rabbi Heidenheim deduces proof to this assertion from the Mishna (Sanhedrin 3:4), which lists those relatives who are disqualified from giving testimony in court about their kin and mentions baal achoto (“his sister’s husband”) separately from gisso (“his brother-in-law”). This implies that a giss refers to a spouse’s sibling, but not a sibling’s spouse. Indeed, Rabbi Tanchum HaYerushalmi (a 13th century exegete who lived in the Holy Land) defines giss as a man’s wife’s sister’s husband, implying that his sister’s husband is not called his giss.
Nevertheless, Rabbi Heidenheim’s argument based on the Mishna is not foolproof: The Talmud (Chullin 18b) relates that Rabbi Yochanan referred to Reish Lakish as “gissa gissa,” which, writes the Ritva, recalls the fact that Reish Lakish was married to Rabbi Yochanan’s sister (see Bava Metzia 84a). Based on this, the Nimukei Yosef (Sanhedrin 6a in the Alfasi pagination) — written by a student of the Ritva — explains that even though the Mishna lists baal achoto separately from gisso, one’s sister’s husband can evidently still be called a giss.
Rabbi Eliyahu HaBachur (1469-1549) explains that the difference between giss and yavam is based on the speaker’s perspective: A man calls his wife’s brother a giss, while a woman calls her husband’s brothers her yavam (even when the mitzvah of yibbum does not apply). For example, when the Midrash refers to Moses from the point of view of his sister-in-law, Aaron’s wife Elisheva, the Talmud (Zevachim 102a) refers to him as her yavam. As we saw earlier, the same is true of two women who are married to brothers, who call each other yevamot (Ruth 1:15). Both a man’s sister’s husband or his wife’s brother can thus be called giss, so two men married to two sisters are called gissim. HaBachur concedes that a man might calls his brother’s wife or his wife’s sister gisato, but this is a borrowed meaning rather than the primary meaning of the term.
It is interesting to consider the etymology of the Mishnaic Hebrew word giss, because the root GIMMEL-SAMECH does not appear in the Bible, and, in fact, the two letters GIMMEL and SAMECH never appear next to each other in the entire Bible! When we look at the Mishna, we find words derived from this two-letter string with various meanings, including: “mixing” (Pesachim 5:10, Yoma 6:7, Avot 6:6, Machshirin 5:11), “army” (Rosh Hashanah 2:5, Yevamot 16:7, Bava Kama 10:2), “thick” (Peah 6:11, Demai 2:4-5, Sheviit 4:1, Shabbat 4:1, 8:1, 24:2, Pesachim 4:3, Yoma 8:2, Kiddushin 1:4, Bava Batra 5:5, Avodah Zarah 1:6, Chullin 2:7, 3:1, 6:7, 9:3, Bechorot 3:1, 4:1, 4:5, Keilim 17:12, 27:11), and “familiar/intimate” (Yevamot 4:10, Sotah 1:6, Gittin 7:4, 8:9, Eduyot 4:7, Avot 4:7).
Rabbi Yaakov Emden (1697-1776) submits that giss in the sense of “brother-in-law” relates to the “familiar/intimate” meaning of the GIMMEL-SAMECH root, as it connotes closeness and familial intimacy. We may even argue that all the various meanings of GIMMEL-SAMECH in Mishnaic Hebrew are actually derived from the core meaning of “mixing.” An “army” is a mixture of various fighters and soldiers joined together for a common cause, “thickness” is a mixture of mass concentrated in one place, and “familiar/intimate” refers to the joining of two parties who grow close with one another. In light of this, it makes sense that giss/gissa is derived from this root because it denotes the intermarriage of families mixing together in matrimony. This explanation is reminiscent of Rabbi Pappenheim’s understanding of the root BET-MEM cited above.
What is quite fascinating is that the term gassut or gassut ruach refers to “haughtiness” (Avot 4:7 and Targum to Psalms 10:2, 10:4, 76:13,101:5, Proverbs 16:18), with the arrogant person feeling “higher” and “more important” than others. This would mean that words related to giss are semantically similar to Rabbi Mecklenburg’s abovementioned understanding of the term yibbum as an expression of “elevation.”
In Talmudic Aramaic, the word gissa also means “side” (see also Targum to Lev. 3:4 and Isa. 60:4, 66:12). Perhaps this relates to the sibling-in-law as figuratively on the “other side” of a proverbial family tree.
Finally, Rabbi Yonah Ibn Janach (990-1050) writes that the Biblical Hebrew word choten, which usually means “father-in-law,” can also mean “brother-in-law.” He adduces this assertion from his understanding that Chovav ben Reuel was a son of Moses’ father-in-law Jethro/Reuel (Num. 10:29), and the Bible describes Chovav as Moses’ choten (Judges 4:11). However, Radak (1160-1234) disagrees with this position and clarifies that Chovav is another name for Jethro, while Reuel was Chovav/Jethro’s father. According to Radak, Chovav was Moses’ father-in-law (choten), so there is no proof that choten can mean “brother-in-law.” Ibn Janach and Radak seem to disregard the Midrashic position that both Reuel and Chovav are alternate names for Jethro.
Interestingly, there is precedent for Ibn Janach’s assertion in other languages, as the Akkadian cognate of choten can mean both “father-in-law” and “brother-in-law.” Similarly, we find a semantic parallel to this in Yiddish in which the words shvugger (“brother-in-law”) and shver (“father-in-law”) ultimately derive from the shared etonym swehuraz in proto-Germanic and swekuros in proto-Indo-European.
* NOTE: HaBachur actually vowelizes the word as gass instead of giss. However, Rabbi Yosef Teomim-Frankel (1727-1792), author of the Pri Megadim, points out that sometimes the word is written with a YOD in between the GIMMEL and SAMECH, which supports vocalizing the GIMMEL with a chirik, as is the common practice. In some versions of the Mishna (like that printed in the Jerusalem Talmud and the Kaufmann MS), the word is spelled with an initial ALEPH, making it agiss, instead of giss. In Modern Hebrew, ALEPH-GIMMEL-SAMECH, or agas, means “pear,” while in the Mishna (Kilayim 1:4, Maasrot 1:3, Uktzin 1:6) it certainly refers to some sort of fruit. Ironically, agiss has become the accepted way of spelling “Huggies” (like in the brand name of diapers) in Israel.