You will be filled with drunkenness and sorrow,
The cup of horror and desolation,
The cup of your sister Samaria.
The context of this verse brings us to a parable laid out in the book of Ezekiel. A story is told of two sisters that become wives of a man. They have children and create a large family. The sisters cheat on the man and have many affairs with other men. They are abusive to their children and do all sorts of other awful things. The cheated on man is angry and allows the first sister to go with her lovers. They brutalize and murder her after they use and abuse her. The second sister hears of this, and instead of changing her ways, increases her affairs and terrible behavior. The man announces that he is going to allow the second sister to follow in the footsteps of her sister to end up with the same fate.
The sisters are a picture of two cities of the time – Samaria and Jerusalem and the man is God. It is a warning to the people of Jerusalem. They are following in the ways of the citizens of Samaria, who self-destructed by their selfish and evil behavior. God is going to allow them to continue to follow what they think is right, but that is going to ultimately lead to destruction just like Samaria faced.