'Beware' in the Bible

Beware that Hezekiah does not mislead you by saying, ‘The Lord will deliver us.’ Has any one of the gods of the nations delivered his land from the power of the king of Assyria?

Beware, I am against you.This is the declaration of the Lord of Hosts.I will make your chariots go up in smokeand the sword will devour your young lions.I will cut off your prey from the earth,and the sound of your messengerswill never be heard again.