Which line in the excerpt from The Scarlet Letter by Nathaniel Hawthorne is an example of metaphor?

"I joy to hear it," answered the physician. "It may be that my remedies, so long administered in vain, begin now to take due effect. Happy man were I, and well deserving of New England's gratitude, could I achieve this cure!"

"I thank you from my heart, most watchful friend," said the Reverend Mr. Dimmesdale with a solemn smile. "I thank you, and can but requite your good deeds with my prayers."

"A good man's prayers are golden recompense!" rejoined old Roger Chillingworth, as he took his leave. "Yea, they are the current gold coin of the New Jerusalem, with the King's own mint mark on them!"