Your charm so strongly works ’em
That if you now beheld them, your affections
Would become tender.
– William Shakespeare
The Tempest, Act 5, Scene 1. Ariel tells Prospero that his magic tricks have worked successfully on his enemies. So much so that if Prospero saw them Ariel says he would feel bad for them. They have been confined spellbound in a grove of trees by Prospero’s magic.