2:204
And of the people (is the one) who pleases you (with) his speech in the life (of) the world, and he calls to witness Allah on what (is) in his heart, and he (is) the most quarrelsome (of) opponents.

19:97
So, only We (have) made it easy in your tongue, that you may give glad tidings with it (to) the righteous and warn with it a people hostile.