Judicial enforcement of Islamic dowry-on-divorce agreements

[Volokh, Eugene]

Mohammed Zawahiri and Raghad Z. Alwattar were married, in an arranged
marriage.  The day of the wedding, Zawahiri signed a "mahr" under which
he promised to pay his wife $25,000 in the event of divorce.  A few days
ago, the Ohio Court of Appeals
(http://www.sconet.state.oh.us/rod/docs/pdf/10/2008/2008-ohio-3473.pdf)
held that the agreement was unenforceable under generally applicable
Ohio prenuptial agreement law (chiefly because it was "presented a very
short time before the wedding ceremony and postponement of the ceremony
would cause significant hardship, embarrassment, or emotional stress,"
and because "Zawahiri did not have the opportunity to consult with an
attorney prior to signing the marriage contract"); this may well be
right.  
 
What particularly interests me, though, is the trial court's alternative
basis for its decision, on which the appellate court didn't opine:  The
First Amendment barred enforcement of a mahr -- just as it would bar the
enforcement of an agreement to give a Jewish religious divorce (citing
an unpublished Ohio decision, Steinberg v. Steinberg, 1982 WL 2446
(Ohio. App.)).  Though the mahr requirement "seems less like a religious
act than the participation in a religious divorce ceremony," "because
the obligation to pay $25,000 is rooted in a religious practice, it is
similarly a religious act" and a court therefore can't order the husband
to make the payment.  I've put the trial court decision online at
http://volokh.com/files/zawahiri.pdf .

Could that be right?  Is it even constitutionally permissible to
categorically refuse to enforce all contracts -- including those that
call for what would otherwise be seen as secular behavior -- because
they are "rooted in a religious practice"?  Or would such a denial of
civil court access to people who seek enforcement of contracts, simply
because the contracts are "rooted in a religious practice" (and don't
require any determination of religious truth or religious law, coercion
of inherently religious conduct, or supervision of religious
institutions or rituals), itself violate the Free Exercise Clause?

Eugene