While reading this Apocryphal book about the sons of Yisrael (Testaments of the Twelve Patriarchs: Book of Levi Verses 51-52) it is stated that קהת means "beginning of majesty and instruction". Elsewhere I saw it be stated to mean "assembly" as well. What does the name mean?
The verse in Bereishis 49:10 which uses a verb that shares the same root is perhaps a good starting point. It writes there:
לֹֽא־יָס֥וּר שֵׁ֙בֶט֙ מִֽיהוּדָ֔ה וּמְחֹקֵ֖ק מִבֵּ֣ין רַגְלָ֑יו עַ֚ד כִּֽי־יָבֹ֣א שילה [שִׁיל֔וֹ] וְל֖וֹ יִקְּהַ֥ת עַמִּֽים׃
The scepter shall not depart from Judah, Nor the ruler’s staff from between his feet; So that tribute shall come to him And the homage of peoples be his. (Sefaria translation)
As you can see it contains the word "יִקְּהַ֥ת" which has the same etymology as the name Kehas.
The Ramban helps provide a clear definition and brings numerous examples of the same word, and starts be explaining it in the context of the verse above, as "אסיפת העמים" - "the gathering of the nations". He then questions it though and explores other options. He writes as follows:
[With regard to the phrase, "nations will gather (yikehas)," Rashi explains that it means,] "a gathering of nations, as it is stated (Yeshaya 11:10) 'Unto him shall the nations seek.' Of similar meaning is the word in (Mishlei 30:17) 'The eye that mocks the father, and despises the gathering of (yikehas) the mother,' [as it means] the gathering of wrinkles on her face due to her old age. And in the Gemara (Yevamos 110b), [we find a similar meaning of this word]: 'They gathered assemblies (mekahu kehiasa - Refer to Rashi there for this variant version) in the streets of Nehardea.” It could have also said an assembly (kehias) of nations [in the verse, instead of yikehas." That is] the language of Rashi. And it does not appear that "the gathering of (yikehas) of the mother" can be explained as the assembly of the mother. And also the expression, "mekahu kehiasa" is only an expression of refutations and challenges, as they would be challenging and refuting it with many questions. Since one who has difficulty with something is called kohehin the language of the sages (Talmudic Aramaic); as they said in Midrash Chazit (Shir HaShirim Rabbah 3:8), "'All of them brandishing the sword' - that they would all learn the law like a sword: that if a matter came to their hands, the law would not be challenging (koheh) to them." And so too are there many [other examples] there. And from [this usage], they said in the gemara (Nazir 65b), "Rabbi Yehoshua kihet and purified [it]," as he challenged many things about it and broke all of the [arguments] that were making it impure, until he forcibly purified it. And so [too], we have found in old textual variants of the gemara (Bava Metzia 52a), "One who kehi for a coin is called an evil soul," since he is exacting about it and is challenged to get it from his friend. And the grammarians (Radak and R. Yonah Ibn Jenach) say that the root of yikehas is yakeh, and that its understanding is [that it is] an expression of discipline and acceptance of command, [such that] "the nations yikehas" is that they will listen to him and do everything that he will command upon them. [And] "he despises the yikehas of the mother" is [that he despises] to accept her command. And that which is correct in my eyes is that it is from the usage (based on Yirmiyahu 31:29), 'One who eats unripe grapes, his teeth will tikahena.' And its root is kehas, and the [first letter,] yod in it is like the yod [at the beginning of] yitshar. And the matter of all [of its usages] is weakness and breaking: It is saying [here] that the rod of the taskmaster will not depart from Yehudah until his son, who [brings] the weakness of the nations and their breaking, arrives - as he will weaken all of them with the blade of the sword. And so [too], "If the iron kehah" (Koheles 10:10) - that it has become weak and cannot cut, like a knife "that has sat," in the language of the sages (Beitzah 28b), or that has become a little broken and has nicks in it. And so [too] did I also find there in Midrash Chazit (Shir HaShirim Rabbah 1:12), "The Holy One, blessed be He, made appear a good scent from the spices of the Garden of Eden, and their souls were (Shir HaShirim Rabbah 3:8) koheh to eat. They said to him, 'Moshe, our teacher, give us what to eat.' He said to them, 'So did the Holy One, blessed be He, say to me, "all sons of foreigners may not eat from it."' They stood up and separated the foreigners from among them and their souls were koheh to eat, etc." And the matter is that their souls were weakened and broken in their bodies from the greatness of their desire to eat from the Pesach sacrifice in which the good smell had cleaved. And so [too], " the law would not be koheh to them," [means that] it be weak and unsure in their hands. And "mekahu kehiata" is [that] they would ask challenging questions that would weaken the soul, because of their great effort (pain) and research. Or it is an expression of breaking and refuting, like the expression (Kiddushin 13b), "Rav Acha refuted." And so [too] did they say (Mekhilta, Parshat Bo 18), "You too should hekaheh his teeth" - [which means] break them or weaken them with your words. [It must also mean weaken] as unripe grapes weaken, and do not break; but weakening and breaking are the same [general] idea, and kehiah includes both of them.
So from this the name Kehas could conceivably mean one of three things:
- An expression of gathering
- An expression of acceptance
- An expression of weakness / breaking