Not Saying Hashem’s Name in Vain
The Gemara in Nedarim (7b) says, “Rav Chanin said in the name of Rav: Whoever hears the utterance of the Divine name [in vain] from his friend has to excommunicate him.
Berachos
The severity of uttering the Divine name needlessly, and how the Sages introduced substitute words for vows to avoid it.
The Gemara in Nedarim (7b) says, “Rav Chanin said in the name of Rav: Whoever hears the utterance of the Divine name [in vain] from his friend has to excommunicate him.