An iron rule of life is to be careful what you wish for.
For a moment he came close to breaking his iron rule of not eating anyone that could talk.
But no one knows better than I the dangers of living by iron rules.
The "iron rule," he said, is never to be away for more than 14 days.
In our outfit it is the iron rule of survival.
Henceforth we live by the iron rules as my husband made them.
He wants to unite all men but under his iron rule.
This is an iron rule that has not changed for four thousand years.
I have learned one iron rule when it comes to war.
Even within science itself there was a protest against the iron rule of reason.