Siman 125

There are three sanctifications in the order of the prayer: the kedushah of "Yotzer," in which we recount how the angels sanctify His Name, may He be blessed. And the kedushah of "Uva LeTziyon" was instituted for the sake of study, as it is stated at the end of Sotah and will be explained in siman 132. And the primary kedushah is in the Shemoneh Esrei prayer in the blessing of "Atah Kadosh," and this is where we sanctify His Name, may He be blessed. Therefore, we are obligated to stand during this kedushah, and with feet aligned just like in the prayer itself, which is not the case with the other two sanctifications. And from the essence of the kedushah, we should have said "Kadosh, Kadosh..." immediately after the sheliach tzibbur finished "Mechayeh HaMeitim," except that there is no kedushah without an invitation. Therefore, first the sheliach tzibbur invites us to say "Kadosh," and for this he says beforehand "Nakdishach VeNa'aritzach" or "Nekadesh Et Shimcha." And this is a preparation and invitation to say "Kadosh," just as before "Amen, Yehei Shmei Rabba," which is the essence of the Kaddish, the sheliach tzibbur says beforehand "Yitgadal VeYitkadash," which is also a preparation and invitation.

And behold, our teacher, the Beit Yosef, wrote: The congregation does not say "Nakdishach" with the shaliach tzibbur, but rather they remain silent and focus on what the shaliach tzibbur says until he reaches the Kedushah. Then the congregation responds "Kadosh." Thus far his words. And this is for the reason we explained, that the shaliach tzibbur prepares them and invites them to say "Kadosh." And just as the congregation does not say "Yitgadal v'yitkadash" but rather begins from "Yehei shmei raba," so too regarding Kedushah: the congregation must begin from "Kadosh" and not say "Nakdishach." And there are still some places where the custom is so. However, in all our regions, the congregation also says "Nakdishach" or "Nakdesh." And there is no concern in this, and we all invite ourselves to the Kedushah. According to this, we should also say "Le'umatam baruch yomeru," and likewise "Uv'divrei kodshecha...", and this we do not practice (see Beit Yosef and Taz). And it can be said that only before the Kedushah do we invite ourselves, but within the Kedushah we do not wish to interrupt with the preparation for the Kedushah, and it is sufficient with the shaliach tzibbur alone. (And one should not ask regarding the fact that they begin with "Kadosh," which is in the middle of a verse, for we have already explained at the end of siman 51 that regarding Kedushah there is no concern, see there.)

And one should lift the eyes toward the heights at the time that they say Kedushah, but his eyes should be closed. And the Tur brought this matter in the name of Sefer Heichalot, that thus the Holy One, Blessed be He, commanded to teach us to lift our eyes toward the heights during the recitation of Kedushah. And thus said the Holy One, Blessed be He: That I have no pleasure in the world like that hour when their eyes are lifted to My eyes, and My eyes are to their eyes. And at that hour I grasp My throne of glory in the image of Yaakov, and hug it and kiss it, and mention their merit and hasten their redemption; see there. And likewise they sway their bodies, and lift the heels of the feet from the ground. And thus it is brought in Midrash Tanchuma (Parshat Tzav 8) on the verse "and with two he would fly" – that from here they instituted to fly on one's feet at the time that they say "Kadosh, Kadosh, Kadosh." And likewise during "Blessed is the glory of Hashem from His place" and during "Hashem shall reign," he should fly on his feet (Magen Avraham in the name of the Shelah). And it seems to me that for all three "Kadosh" – he should say them in one flying motion. (And it seems that this is what the Magen Avraham wrote: not like those who jump and leap; see there in subsection 2. And perhaps his intention was regarding jumping completely off the ground.)

The congregation should not answer "Kadosh" until the shaliach tzibbur finishes "And they called one to another and said." Nevertheless, if one answered at the time he said "And they called"—he has fulfilled his obligation. And there is one who says that he has not fulfilled his obligation (see Sha'arei Teshuva subsection 2), but the primary view is like the first opinion. And it is simple that what is added on Shabbat, "Then with a voice...", "From Your place...", and likewise in Musaf—these are not from the essence of the Kedushah, and in a place where it is forbidden to interrupt, one should not say this. And one must say "Kadevar ha-amur be-shirei uzzekha," the heh of "ha-amur" with a kamatz (Magen Avraham). And the shaliach tzibbur should be careful to finish "Facing them they say, Blessed" and likewise "And in Your holy words it is written, saying" before the congregation answers "Baruch" and "Yimlokh" (ibid.). Our teacher, the Rema, wrote that one who already said Kedushah and comes to the beit knesset at the time of Kedushah—he returns and answers Kedushah with the congregation, see there. And even many times, unlike the one who wishes to say that one only says Kedushah one time (see Beit Yosef). And it has already been explained that one must align his feet at the time he says the Kedushah with the shaliach tzibbur. And the Ari, of blessed memory, warned very much about this. And it is forbidden to speak in the middle of Kedushah just as during the Tefillah. And one must intend during Kedushah to sanctify His Name, may He be blessed, so that holiness from above shall rest upon him. And he should intend to fulfill with this the positive commandment of "And I shall be sanctified in the midst of the children of Israel." And the Ari, of blessed memory, warned very much about this. And know that the Sephardim, even the shaliach tzibbur says "Atah Kadosh." And the Ashkenazim practice that he says "Le-dor va-dor nagid...". And it appears to me that an individual who performs Kedushah according to our custom should say "Atah Kadosh," for "Le-dor va-dor" was only instituted for the shaliach tzibbur in the congregation.