Re Tuck [1978]

Denning saw no reason why a testator or settlor should
not leave the decision of whether a condition subsequent was met to his
trustees or to a third party.
Hence any uncertainty in the requirement of being of
the Jewish faith and married to an ‘approved wife’ could be cured by a
provision that disputes were to be decided by a chief rabbi.
But though all the judges upheld the settlement, there
was not a majority behind Denning’s basis for doing so.