The airman’s right to modify the oath to fit his lack of religious belief is not in question outside the Air Force, a defense official who discussed the matter on the condition of anonymity said Tuesday.

“I’ll tell you that there is no legal requirement to say ‘So help me God’ in any federal oath/affirmation by a person taking the oath,” the official, who was not authorized to speak publicly about the matter, said in an email. “That is, saying ‘So help me God’ in any federal oath is optional at the discretion of the person taking the oath (not the person administering the oath).”