Each new morn
New widows howl, new orphans cry, new sorrows 
Strike heaven on the face, that it resounds 
As if it felt with Scotland and yelled out 
Like syllable of dolor. (4.3.4–8) 

Here Macduff laments the effects of Macbeth’s tyrannical rule on Scotland, where the heavens echo the cries of the widows and orphans left behind by Macbeth’s killing spree. By Act IV, Scotland has become a place of widespread grief and sorrow. Macduff, perhaps speaking figuratively, says that the grief of orphans and widows strikes heaven and makes it scream out in pain. Once again, the physical setting mirrors the state of human events in the play.   

Alas, poor country! 
Almost afraid to know itself. It cannot 
Be called our mother, but our grave, where nothing, 
But who knows nothing, is once seen to smile; 
Where sighs and groans and shrieks that rend the air 
Are made, not marked; where violent sorrow seems 
A modern ecstasy. 
(4.3.166–172) 

In this passage, Ross describes the hellish place that Scotland has become under Macbeth’s rule. He can no longer think of Scotland as his mother country, but only as his grave. No one ever smiles, and the sound of groaning and shrieking has become so common that people have stopped noticing. “Violent sorrow” has become the dominant mood throughout the whole country.