What is an example of a pun in The Book Thief?

A pun is a joke or has an ambiguous meaning. Shakespeare's plays are full of puns. This example is from the opening lines of Richard the Third. Gloucester. Now is the winter of our discontent

Made glorious summer by this sun of York; The pun is based on the two meanings of the spoken Word sun ie son and sun. Gloucester refers to Richard both as the son of the Duke of York and also a bright sun which would chase away their wintry blues.