Parashas Yisro · Passuk 20:7
Chabad.org — English translation + Rashi
Torah Temimah points to Berachos 33a (verified).
Sefaria — Exodus 20:7
Sefaria — Berachos 33a
E-Daf — Berachos 33a
English: Whoever recites an unnecessary blessing transgresses “You shall not take [the Name in vain].”
On the daf / in context: See the cited source for the full section.
Derash on the verse.
Uttering the divine Name in a blessing that is not needed falls under the prohibition of taking the Name in vain.