Is the idiom of or mind?

The idiom "of or mind" is not a standard English idiom. It seems like you might be thinking of a different idiom, or perhaps there's a misunderstanding about the phrase.

Could you please provide more context or clarify what you mean by "of or mind"?

For example, are you thinking of:

* "Of one mind": meaning to be in agreement or have the same opinion.

* "Peace of mind": meaning a state of calmness and tranquility.

* "Change of mind": meaning to alter one's decision or opinion.

Let me know, and I can help you understand the correct idiom.