Q: Is there a deeper significance to the last word Itborach in the Ame Yehey Shemey Rabba line of the Kaddish?

A: The most important part of Kaddish is the congregation’s response and central line: Yehai shmeh rabbah mevarach leolam ulolmay olmaya, (“May His great name be blessed for ever, and to all eternity”). According to the Targum Yerushalmi this response is an Aramaic translation of the Hebrew Baruch shem kevod malchuto leolam vaed. (Blessed be the name of His glorious kingdom for ever and ever), (Genesis 49:2 and Deuteronomy 6:4, and is similar to the wording of Daniel 2-20.) Although it is not a complete translation as it lacks the kevod malchuto. (See Emeth Leyaakov P. Vayehi for an explanation). According to the Talmud this was Yakov Avinu’s praise to Hahem when he realized that his children were all with him as they proclaimed the first Shema Israel. (see Pesachim 56-a). In that sense, Itbarach (be His Name blessed) is separate from Yehei Shmei Rabah.
There are indeed three different traditions in answering Yehei Shmei Rabah, and they convey different meanings to “itbarach’

1) Ashkenazi minhag (see Tur, Bet Yosef O.C. 56 , Abudraham and Hagrah ibid., Rambam, H. Tefilah 9-1) is to recite only till olmayah. This response consists of 28 letters, alluding to the word “koach”, and reminding us “That whoever responds Yehe Shmei with all his “koach” or might (utmost concentration Rash“i), any judgement against him is torn up (Shabat 119b). It also alludes to the first verse of the Torah that similarly contains seven words and has 28 letters. According to this tradition, itbarach is a section apart consisting of eight praises, and reverts to the beginning of kaddish. Together with Itgadal, veitkadash, it entails ten expressions of praise that represent the Ten Commandments. The first two terms stand separately, as the first two commandments did, which were expressed by Hashem Himself . (Shibolei Haleket ibid.). This would place “itbarach” as representing: “Thou shall not take the name of Hashem in vain” . This is the source of the holiness of all blessings and brachot.

2) The customary Hasidic tradition (R. Yosef Gikatilia, Bet Yosef and Mechaber O.C. 56 et al). is to include Itbarach, in the Yehey shme rabah declaration. They vehemently claim that it is an integral part of this praise and has to be said together. Tur (ibid..) mentions a minhag were Amen is said after ‘itbarach” This is based on a severe warning mentioned in a Midrash of not separating between the two. The reason is basically of Cabalistic nature. R. Bachye (Shemot 2-24) compares kaddish to the cry of the children of Israel from their bondage in Egypt, and Hashem listening and remembering His covenant to them. Together with Yehei shmei rabah, the “itbarach” represent the Ten Sefiroth and one should not separate between “the Keter and the Ein Sof”. It is interesting to mention that with “itbarach” we have now 34 letters, also alluding to “might“, but more correctly “his might’ (bechol kocho) as in the Talmudic expression quoted before (Derishah ibid.)

3) The Separadic minhag, (Hoarizal, Shelah, Kaf Hachaim, Ben Ish Hai P. Vayehi et al) is to respond Yehei shmei rabah through “Da’amiran Be’alma” which consist now of twenty-eight words instead of letters,. This is also based on cabbalistic teachings.

It is worth mentioning that Mishne Berurah (ibid.) advices to add Itbarach to Yehe Shmei ( in places where hefsek is not an issue) but to separate slightly between them.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a.