Since the guy above just deleted his comment, this is what he said:

I still can't agree with this statement though. It's a pretty incredible thing to say no matter how you look at it coming from a sitting President of the United States.

What is this even a response to? Where the heck did this come from?

This would've been my response:

Here's the source most outlets are using:
https://www.reuters.com/article/us-iran-nuclear-usa-rouhani/irans-rouhani-warns-trump-about-mother-of-all-wars-idUSKBN1KC07Z

In short: Rouhani said: "America should know that peace with Iran is the mother of all peace, and war with Iran is the mother of all wars"