The sop as prophecy. Matthew, Mark, and Luke use the sop at the Last Supper to show how a disciple’s betrayal fulfills Scriptural prophecy. And John has Jesus use the same sop as a means of prophesying that Judas will be that betrayer.
Shakespeare foresaw the melting of the polar ice caps:
. . . the bounded waters
Should lift their bosoms higher than the shores
And make a sop of all this solid globe
(From Act 1, Scene 3 of Troilus and Cressida.)
Interesting, though, that like the gospel writers, Shakespeare prophesies with a sop.