The terror of a king is like the growling of a lion;
whoever provokes him to anger forfeits his life.
This proverb is giving warning to those subject to another's power. Just as the person with power should take heed not to be provoked, so the person under their power needs to exercise proper wisdom not to provoke. Many persons have lost jobs, they claim because of principle, but in truth because their pride was hurt or they simply would not do their jobs. See how unreasonable their bosses are! Students may be given "one last" warning to come to class on time or turn in homework and they fail to do so. They are surprised by the anger of the teacher or principal. Even Christians are guilty of such behavior, excusing themselves by claiming religious persecution.
And so it is with many people in their attitude towards God. They hear warning after warning about provoking God's wrath, and they ignore or even mock the very warnings. Like the student who ignores the principal's warning and continues his ways, or the worker who keeps trying to get away without working, they believe they can continue to go their own ways.
But God will not be mocked. His judgment will come. Therefore, pray for such persons. Pray that they will receive such mercy as to hear and heed the warnings of judgment. Pray that their eyes will be open to their sin that provokes. And pray that we will witness through our lives good fear of our God who shows a love that is wondrous precisely because of his powerful wrath. For what wondrous love is this that God the Son would forfeit his own life and receive such anger for us?