Levítico 19:36 Halajá: Sefer HaChinukh, Sefer Chasidim, Kitzur Shulchan Arukh & Mishneh Torah, Positive Mitzvot

However, regarding the matter of lashes, there is a difference between [the examples]. As all those [simply] specified in one negative commandment only receive one [set of] lashes — for example, “the wage of a harlot and the price of a dog” (Deuteronomy 23:19); and “leaven and [...] honey” (Leviticus 2:11); “the case of a stranger [or] an orphan” (Deuteronomy 24:17), and all that is similar to them. But the negative commandments that [also] have a general category and are specified at the beginning or end [of the category] — for example, this negative commandment that specified “uncooked and boiled” and is [then] generalized, “Do not eat [...] but only roasted with fire”; and so [too], with a nazerite (Numbers 6:4), “from anything that is obtained from the grapevine [...] may he not eat,” and afterwards it specifies, “seeds [...] or skin,” (“and grapes wet and dry,” Numbers 6:3) — with these and those similar to them, we give lashes for each and every one. [This is] because the inclusion of the specification that was not needed indicates lashes for each one [of them], as we have said. And the teacher was prolific in his proofs about this in the ninth shoresh in his Book of the Commandments — that the calculation of commandments is not the same as the calculation of [which commandments require] lashes [independently]. And that which I have said that Ramban, may his memory be blessed, will count each of the ones specified by their names individually — each one by itself — only when they are separate in their content, as we have written; [it] is, for example, [in the case of] “leaven and honey,” [and] “the wage and the price.” But in a case where it is the same content — even if they are specified by different names — they are only counted as one commandment. For example, “All male firstborns that are born in your herd and in your flock” (Deuteronomy 15:19) is only one commandment to sanctify all of the firstborns; and the specification is [also] only one commandment. And so [too], “All tithes of the herd or flock” (Leviticus 27:32) is only one commandment to separate to give the tithes of these animals. And so [too], “Judges and officers” (Deuteronomy 16:18) is only that we should establish justice through these people and it is one commandment. And so [too], “An honest balance, honest weights, an honest ephah, and an honest hin” (Leviticus 19:36) is all one commandment, that we should not lie about measures.

“Who teacheth us more than the beasts of the earth, And maketh us wiser than the fowls of heaven” (Job 35:11). “Who teacheth us more than the beasts of the earth,” (tells) a man to teach his son to be more faithful than a dog that is faithful to its master.¹Horayoth 13a. “And maketh us wiser than the fowls of the heaven,” (this verse) tells a man to learn from the hoopoe, the hen of the prairie. Because, in the time of Solomon, it (hoopoe) did not fulfill its faithfulness to the ruler of the sea involving the “shamir” put in its charge, it choked itself.²Louis Ginzberg, Legends of the Jews (7 Vols.; Philadelphia: Jewish Publications Society, 1909-1938), VIL 299, note 85. Therefore let the remainder of Israel apply to itself the syllogism and take a lesson from the hoopoe which does not receive reward for guarding its faithfulness, or punishment for not safeguarding it. You, however, who are punished when you lie, is it not a matter of course, that you should not commit wrongdoing, speak lies, or let deceit be found in your mouth, one thing in your mouth another in your heart, but rather only truth, which is the seal of the Holy One, blessed be He.³Shabbath 55a. And so did the sages say, “a just hin” (Lev. 19:36), your “yes” should be yes, and your “no” no. ⁴Baba Metzia 49a. The gestures of a person and the hintings should be just, also the movements of the head. When he bends his head and says “No” he moves his head to the sides, also let all his limbs be true.⁵Shebuoth 31a. (And so is it written) “Sincerely do they love thee” (Cant. 1:4). Rav Tavid said, “If they were to give me the vaulting of the world I should not change my words.” ⁶Baba Metzia 49a. Anyone who varies from his word is regarded as if he worships idolatry,⁷Sanhedrin 92a. for it is said, “And I shall seem to him as a mocker” (Gen. 27:12), and it is written, “They are vanity a work of delusion” (Jer. 10:15). And so is the punishment of liars, even when he speaks truth they do not listen to him.⁸Ibid., 89b. But each one who speaks truth and does not speak or even think falsehood, his words are fulfilled, he decrees below and the Holy One, blessed be He, fulfills it from above. Concerning this it is said, “Thou shalt also decree a thing, and it shall be established unto thee” (Job 22:28).⁹Ketuboth 77b.

Likewise, if a person promises someone a small gift and he depends on it being sure that it will be given to him. If the donor changes his mind and does not give it, he is considered lacking in honesty. But [if he promised] a large gift [and then changed his mind], he is not considered lacking in honesty, as the [prospective recipient] did not depend on it. Nevertheless, at the time that he promises to make a gift, he has to act in good faith and not have the intention of changing his mind; for to say one thing, while thinking the opposite is forbidden by the Torah, as it is said, "You must have a just eifah and just hin."¹³Leviticus 19: 36. Why does the Torah mention a just hin? Is not hin included in the term eifah [both are units of measurement]? [Our Sages explain:] "Let your hein (yes) be just and let your "no" be just."¹⁴Note the similarity of the words hin and hein. The above-mentioned law [refers to a promise made] to a rich man, but if someone makes a promise to a poor man whether [he promised] a small gift or a large gift, he may not legally change his mind, because [his promise] is considered as a vow. Even [if he did not verbally express his promise] but only made up his mind that he would give, he must carry out his intention.