But wherefore could not I pronounce “Amen”?
I had most need of blessing, and “Amen”
Stuck in my throat.

– William Shakespeare

Macbeth, Act 2, Scene 2. Macbeth tells his wife that when one of Duncan’s servants cried “God bless us” in his sleep, he was unable to speak the word “Amen.” Laden down with guilt, Macbeth seeks forgiveness from God but is unable to get it. He knows he has gone against God and committed the most grevious sin of regicide.