"You shall not take the name of the L-rd, your G‑d, in vain"Exodus 20:7.

It is forbidden to needlessly swear in the name of G‑d.

Examples:

  • To swear falsely regarding something that is an obvious untruth [e.g., to swear regarding a simple pebble that it is made of gold].
  • To swear that a phenomenon that is known to be impossible has occurred.
  • To swear to do something that violates a Torah commandment.
  • To swear in attestation of an obvious truth, e.g., to swear that all that are slaughtered die.