In the Old Testament reading, Isaiah pronounces the judgment of God on someone named Shebna, who is called the "master of the palace." Isaiah's message is grim, but it's meaning isn't all that clear.
At least forty-eight times (and sometimes more) in every Spider-Man movie, someone is required to say "with great power comes great responsibility." And while it can get old after a while, it's also true. Being "master of the palace" means that you are second only to the king. You exercise the king's power, but you are responsible to the king for what you do with his power.
The Backstory: Shebna has the great power part down, but (according to Isaiah) Shebna has blown the great responsibility part. Shebna has done things his way, and because of this, he's done as master of the palace.
Tomorrow, we'll look at how this Old Testament personnel problem relates to the rest of the readings in Ordinary Time.