For a chasid, each of the responses in congregational prayer — such as Amen [to blessings], or Amen, yehei shmei rabba... [to Kaddish] or Baruch hu uvaruch shemo [after G‑d's Name in a blessing], is a matter of cosmic consequence. A chasid should be (and is indeed) sensitive to the meaning of the words keil melech ne'eman — "G‑d, faithful King," which are the soul of the word Amen. In the same way, a chasid should (and indeed does) feel and identify with the inner meaning of the words, Baruch hu uvaruch shemo — "Blessed be He and blessed be His Name."

To explain: The level of Divinity (the Ohr Ein Sof, G‑d's infinite light) which is signified in this phrase by hu is the same as the transcendent level of Divinity (lifnei hatzimtzum) signified by hu in another phrase, atah hu Havayah l'vadecha (lit., "You are He Who is G‑d alone"). When in the first half of the former phrase (baruch hu) we use the root beirach to signify "drawing down" and speak of drawing Divinity down to this world, we are speaking of the same transcendent level of Divinity signified by the first half of the latter phrase, atah hu, which addresses the very essence of the Luminary Himself. And in the second half of the former phrase (u'varuch sh'mo), the Name referred to is the Four-Letter Name that signifies Divinity in the pristine state that precedes the tzimtzum.

Moreover, while meditating on the above insights into baruch hu u'varuch sh'mo, a chasid grasps that ultimately, the drawing down of the levels of Divinity signified by the terms hu and sh'mo surpasses the aloof and ethereal state denoted by the phrase atah hu Havayah l'vadecha, in which the levels of Divinity known as hu and havayah are alone, so to speak, and do not relate downward to the created universe.

Chasidut should be studied with intense involvement; it should be taken to heart.

Chasidut should be studied with intense involvement; it should be taken to heart. Those who study Chasidut with themselves in mind and with deep concentration understand the difference between the first tzimtzum of the light of G‑d's infinity and the subsequent tzimtzumim that transpire within the chainlike downward progression of spiritual worlds. Whereas the latter tzimtzumim reflect a process of diminution the first tzimtzum represents a complete withdrawal The light that radiates after the first tzimtzum is not merely qualitatively inferior to the light that had previously diffused, but utterly different in kind. After each of the other tzimtzumim, by contrast, the nature of the light remains the same, except that it is diminished both quantitatively and qualitatively. These terms are all fully explained in Chasidut [and Kabbalah].

G‑d's intent in bringing about the first tzimtzum is that the souls of Israel, by serving G‑d through Torah and mitzvos, should ultimately draw down the transcendent Ohr Ein Sof that radiates in the pristine state preceding the tzimtzum, and infuse it into the attenuated state of revelation that exists after the tzimtzum. This mode of divine service reflects the above-discussed superiority of the downward-oriented level of Divinity represented by the phrase, baruch hu u'varuch sh'mo, over the separate and transcendent level of Divinity represented by the phrase, atah hu Havayah l'vadecha. For the latter phrase represents the Ohr Ein Sof before the tzimtzum as it exists in its own territory, undiffused. The former phrase, by contrast, represents the downward extension of this very same level of light (i.e., the Ein Sof-light in its unmuted state before the tzimtzum, as alluded to by hu and havayah) into the lower state of being that follows after the tzimtzum.

All this is accomplished by the divine service of the Jewish people, who steadfastly recite the response, baruch hu u'varuch sh'mo, with devout concentration.

[Condensed from Likkutei Dibburim V (English translator: Uri Kaploun), section 56.]