grammar - Is the use of whom appropriate in the phrase "You are with whom your mind is."?

And why?

I always see whom used in questions. This is not a question, is a statement. Whom sounds correct to me, but I'm not sure if it is and why.

The "rules" I've seen around are all for questions, not for statements. In this case, "whom" seems the object to whom (hehe) the action of "being with" is performed. Is this correct?

Answer

The distinction as I understand it after reading the comments is essentially about the distinction between the possible sentences:

You are with whoever your mind is with.

and

You are with whomever your mind is with.

My answer is that the latter is correct and the former is acceptable in many variants of modern English.

Reasoning

We say, 'You are with him.'

We do not say, "You are with he."

The above is almost universally true, regardless of grammatical terminology.

We can say, 'You are with whom?'

In many varieties of English we can say, 'You are with who?'

We merely have to extend this series in order to arrive at the two sentences I started with.