The Torah famously commands: “From a false (sheker) matter, you shall distance [yourself]” (Exodus 23:7). Elsewhere, the Bible states that “the remnant of Israel do no iniquity and speak no falsity (kazav)” (Zephaniah 3:13).
A third word for lies is “kachash;” we ask for forgiveness on Yom Kippur for sinning through kachash and kazav. What’s the difference between “sheker,” “kazav,” and “kachash?”
Rabbi Yosef Albo (1380-1444) in Sefer Ha’Ikkarim (2:27) writes that “emet” (truth) is an antonym to both “sheker” and “kazav.” Truth means consonance between a statement and reality, and it also means consonance between what a person verbally expresses and what he thinks in his heart. “Sheker” is dissonance between the former pair, and “kazav” is dissonance between the latter pair.
Rabbi Yehuda Leib Edel (1760-1828) takes issue with Rabbi Albo’s assumption that a statement that truly reflects one’s inner thoughts can be called sheker if it doesn’t reflect reality. He asks: According to this definition, how can the Torah forbid a person from testifying sheker or taking an oath of sheker? After all, a person can only present something as he perceives it.
Indeed, the Talmud (Shavuos 26a) exempts a person from punishment if he swore falsely to something that he thought was true. To Rabbi Edel, this suggests that the definition of sheker cannot be something that is simply objectively untrue; rather, an element of subjective and purposeful deceit must be involved.
Indeed, Rabbi Yaakov Tzvi Mecklenburg (1785-1865) differentiates between “sheker” and “kazav” by writing that “kazav” denotes lying by mistake, while “sheker” denotes purposefully or deceptively saying something untrue. He notes that when the Torah prohibits lying, it states “lo tishakru” (Leviticus 19:11) – as opposed to “lo tichazvu” – which indicates that the prohibition only entails deliberate lying, not mistaken lying.
We can defend Rabbi Albo’s position by suggesting that although “sheker” generally means any false statement (whether made knowingly or not), the Talmud derives from Leviticus 5:4 that the prohibition against sheker is limited to knowingly swearing or testifying falsely.
Rabbi Samson Raphael Hirsch (to Genesis 9:21, 21:23, and 43:11) invokes the interchangeability of kuf and kaf and thus compares “sheker” to “shikur” (drunkard). A drunk person dreams up all sorts of ideas that are outside the realm of reality, and sheker is something that lies outside the realm of the true and real.
The Vilna Gaon (to Proverbs 12:25) differentiates between “sheker” and “kazav” in a different manner. “Sheker,” he maintains, is an immediate lie while “kazav” only becomes false later. For example, if a person says he’ll do something that he never planned to do, he has uttered a sheker. But if he says that he’ll do something that he genuinely planned to do at that moment, but later decided not to keep his word, he has uttered, in retrospect, a kazav.
(Rabbeinu Yosef Bechor-Schor [to Numbers 23:19] also writes that the verb “kozev” is used for someone who doesn’t keep his word.)
Based on this distinction, Rabbi Yehuda Leib Shapira-Frankfurter (1743-1826) writes that the Torah never prohibited saying kazav like it prohibited saying sheker (Leviticus 19:11) because a person can’t technically say kazav. Only later on when a person doesn’t keep his word can one can say in retrospect that he said kazav.
The Malbim in Yair Ohr writes that “sheker” has no validity or truth to it, but “kazav” does because at first it seems to be true; only later is it exposed as a lie.
In Sefer HaCarmel, the Malbim adds that the same utterance can sometimes be described as both sheker and kazav. For example, if somebody purposely says something that will later prove to be false, the statement is immediately sheker from the perspective of the speaker because he knows it’s false. The listener, however, doesn’t know it’s false until later, so for him the statement is kazav.
Hence, when somebody brands fake news as “sheker v’chazav,” he technically is saying that it’s both sheker from the speaker’s point of view and kazav from the listener’s point of view.
Rabbi Hirsch (to Exodus 7:11 and 21:17) maintains that the root kaf-zayin-bet is related to the root kaf-shin-peh, which means witchcraft. He explains that, like witchcraft, kazav only appears to be real on the surface; in the end, though, it reveals itself as wholly untrue. Interestingly, the prophet Ezekiel repeatedly uses the term “kazav” in reference to witchery (see Ezekiel 13:6, 13:7, 13:9, 21:34, and 22:28).
How does the word “kachash” fit into this discussion? “Kachash” is commonly translated as denial, and the same verse that prohibits lying also prohibits kachash (Leviticus 19:11).
The Malbim writes that when a sheker-type lie is first spoken, nobody immediately disputes it, while a kachash lie is disputed before it’s even said. Rabbi Hirsch writes that kachash is a false reaction to another’s claim. He contrasts “kachash” with “ka’as” (anger) – presuming the interchangeability of chet with ayin and shin with samech – and explains that ka’as is a real and justified reaction to someone else’s misdeed, while kachash is an artificial reaction of denial to someone else’s real and justified claim.
R. Yonah Wilheimer (1830-1913) explains that “kazav” and “kachash” refer to two different types of lies. Saying kazav means saying something exists that doesn’t exist while saying kachash means saying something doesn’t exist that does exist. Sheker, according to him, is evidently an umbrella term that includes both of types of lies.
Finally, Rabbi Shlomo Aharon Wertheimer (1866-1935) seems to suggest that the three words in question reflect three different levels of falsehood. Sheker is a statement that everybody knows is false the moment it’s uttered, kachash is a denial that has some plausibility but cannot be disproven outright, and kazav is a lie whose falsity can only be discovered later on.