[Ironword]

I think it was simply a poetic allusion to Providence working even in tumult. No more, no less.

But tumult also has a cause, which can be active or passive (witholding of grace).

[anniegetyourgun]

True, but the phrase doesn't address that. Should he have expounded? Perhaps. Would it have mattered to the masses who don't acknowledge Providence? Probably not.

[rwfromkansas]

Tumult can only be caused by one: GOD. He causes EVERYTHING.