“By spilling a drop of wine, from the Pesach cup for each plague, we acknowledge that our own joy is lessened and incomplete. For our redemption had to come by means of the punishment of other human beings. Even though these are just punishments for evil acts, it says ‘Do not rejoice at the fall of your enemy.’” (Proverbs 24:17)

haggadah Section: -- Ten Plagues
Source: A Different Night Family participation Haggadah