Metaphor in Hamlet
Metaphor Examples in Hamlet:
Act IV - Scene II
"to be demanded of a sponge..." See in text (Act IV - Scene II)
Hamlet explains this metaphor more fully in his next passage, where he states that as servants to the king Rosencrantz and Guildenstern suck up his attention (and suck up to him). In the line, sponge seems like a sneering insult, and one can imagine Hamlet delivering it with disdain.