What did Joshua command to stand still over Gibeon?

Answer: The sun

Joshua said, "O sun, stand still over Gibeon," and the sun stood still until Israel had defeated its enemies.

“So the sun stood still and the moon stopped until the nation took vengeance upon its enemies. Is this not written in the Book of Jashar? “So the sun stopped in the middle of the sky and delayed going down about a full day.””— Joshua 10:13 (BSB)