(Mishnah): A blasphemer is liable only if he explicitly says Hash-m's name.

R. Yehoshua ben Korchah says, during the trial, the witnesses use a euphemism (e.g. Yosi) for Hash-m's name. They say (that the blasphemer said) 'Yosi should strike Yosi';

After reaching a verdict of guilty, before killing him we tell everyone [other than the witnesses] to leave, and we leave the greatest witness, and tell him to say the exact words that he heard;

He says it. The judges stand, tear their clothing and may never sew it back properly;

The second [witness] says 'I heard like him.' [If there are more witnesses,] the third says 'I heard like him.'

(Gemara): Which Lav forbids blasphemy? "Elokim Lo Sekalel'';

What is the source for Kares? "Ish Ish Asher Yekalel Elokav v'Nasa Chet'o.''

What is the source for punishment? "V'Nokev Shem Hash-m Mos Yumas'';

Implied question: According to R. Yishmael [what is the source]? R. Yishmael says that the verse discusses [cursing] judges!

Answer: If it warns about judges, all the more so for Kinuyim (names that refer to Hash-m)! If for Kinuyim there is Kares, all the more so for Hash-m's special name (of four letters - Yud Kei Vov Kei)!

(Beraisa #1): There is a Lav and Kares for Kinuyim, and Misah for Hash-m's special name.