“When a person reaches the expressions of praise of Hashem listed in the Yishtabach prayer, he should not pause at all. What happens if he interrupts his recitation? A fire comes out from the wings of the angels and says that whoever interrupts the recitation of Hashem’s praise should be taken from this world” (Zohar, Terumah 132).
The rabbis took the Zohar’s dire warning very seriously, and they advise us to be careful to say all of these praises without pause. Although the Shelah writes that the fifteen expressions of praise should be said in one breath, the halacha is that it is sufficient to say them without interruption (Mishna Berura 53,1).
When a person is a little behind in his prayers, he might find himself still saying Yishtabach while the rest of the congregation has moved on to Kaddish. Since some authorities consider answering Kaddish to be an interruption, one should try and time the praises of Yishtabach so that he will not have to answer amen in the middle (Kaf Hachaim 53,2). If this cannot be avoided, he should answer amen and then start the praises again from the beginning (Ben Ish Chai, Vayigash 15).
Text Copyright © 2008 by Rabbi Daniel Travis and Torah.org