For with stammering lips and another tongue will he speak to this people.

Indeed, with mocking lips and foreign tongues, He will speak to this people

Thou shalt not see a fierce people, a people of a deeper speech than thou canst perceive; of a stammering tongue, that thou canst not understand.

You will no longer see the insolent, a people whose speech is unintelligible, who stammer in a language you cannot understand.