to delight in: to really enjoy doing something; to like a thing very, very much. Examples:
Trump delights in insulting people who are less powerful than he is. Fucking bully–nothing more despicable than a fucking bully.
Trump delights in his ability to insult women’s appearance on the world stage. What a loser.
How it’s used on the sign: Delight in treasures old and new.
Brought to you by the Anglophone Association for the Promotion of Weird Prepositions.