This is a command to stare at the model of Jerusalem as a symbol of punishing Jerusalem. See how you translated a similar phrase in [Ezekiel 4:3](./03.md). Alternate translation: "Stare at Jerusalem that is under siege" or "Stare at Jerusalem that is under siege, so that it will be harmed" (See: [[rc://en/ta/man/translate/translate-symaction]])
Here "face" is a metonym for attention or gaze. "Set your face" refers to literally staring at something. (See: [[rc://en/ta/man/translate/figs-metonymy]])
# prophesy against it
"prophesy about the bad things that will happen to Jerusalem"