‘Who shall declare his way to his face?’ The implied answer is ‘Often, no one.’ The wicked man often never faces any challenge to his behaviour and therefore goes on in the same track not meeting any resistance or correction.
The words ‘they remain in their tombs’, is literally ‘they keep watch over the heap’, the heap of stones or earth forming the tomb. The verb means to be wakeful over so that sleep is denied in order to prevent any mishap from occurring. This should be seen as a token of respect for the dead, not for any other reason.