Read this excerpt from The Iliad .

First give thy faith, and plight a prince's word

Of sure protection, by thy power and sword;

For I must speak what wisdom would conceal,

And truths, invidious to the great, reveal,

Bold is the task, when subject, grown too wise

Instruct a monarch where his error lies;

Invidious means getting others angry, what key words support this inference?

truths, great, bold
sword, wisdom, subject
speak, wisdom, conceal
protection, monarch, sword