Please note that the term "Blessing" on this page is used euphemistically for the reverse of its meaning.
The punishment for using strong language in addressing Gd: Succah 53a; Megillah 22b
Definition of "Migadef" as 'Blessing' Hashem: Pesachim 93b; Keritot 7a-b; Rashi to Keritot 2a "migadef"
Definition of "Migadef" as Singing to Idolatry: Pesachim 93b; Keritot 7b; Rashi to Keritot 2a "migadef"
Whether the Migadef is punished with Divine Ex-Communication: Pesachim 93b; Keritot 2a, 7b
Whether a Migadef is exempt from bringing a korban chatat [sin offering], since no deed is involved: Keritot 2a [2x]; 3b; 7a-b
Tearing one's clothing, and repairing the tear, upon hearing such a "Blessing": Moed Katan 26a
Whether the witnesses tear upon repeating their testimony, and whether those who hear it from them, and even those who hear it from the listeners, tear: Moed Katan 26a
Comparing a Curse against one's parents to blessing Gd: Kiddushin 30b