Halakhah su Salmi 25:78

"The secret of God is with those who fear Him" (Psalms 25:14). Said Rabbi Simeon: There is no secrecy for heavenly beings, but for terrestrial beings there is secrecy.

Laws of the Congregation's responding to the Kaddish (5 sections): One should have concentration when answering the Kaddish. Rem"a: And one does not interrupt between "Y'hei Sh'meih Rabbah" ("May the Great Name") and "M'varakh" ("be blessed") [Hagahot Asheri in the name of Or Zarua wrote regarding the first explanation: "One should not interrupt between "Sh'meih" and "Rabbah" and according to the explanation of the Ri: one should not interrupt between "Rabbah" and "M'varakh"]. and one should answer loudly and strive to run to hear Kaddish. Rem"a: And one should stand when answering Kaddish and any davar she-bikdushah ("matter in which there is holiness" - a recitation which requires a minyan). And one who comes to synagogue and hears the congregation answering Kaddish answers along with them even though he did not hear the prayer-leader saying "Yitgadal etc." [Hagahot Chadashim on the Mordechai on Brakhot]. And the prayer-leader also needs to say "Y'hei Sh'meih Rabbah...". And when he begins "Yitgadal...", one should say "And now, let power [of YHVH] be magnified..." (Numbers 14:17) and "Remember Your mercy..." (Psalms 25:6).

And [it] is practiced in every place and at all times by males and females. And one who transgresses it and does a thing of those that we mentioned, to imitate them, is liable for lashes. And one who distances himself from all of their customs and from all of their mores, and places all of his heart and his thoughts to God, may He be blessed, and to His precious commandments, 'his soul will rest in the good, and his seed will inherit the land.'