The Hebrew word eder carries two related senses: greatness or magnificence, and a shepherd's mantle or large garment. In Zechariah 11:13, it refers to the robe of a shepherd-prophet.
The shepherd's mantle (eder) in Zechariah becomes a powerful messianic symbol. When the LORD instructs Zechariah to enact the coming betrayal, the prophet is wearing a shepherd's cloak. Jesus, the ultimate Shepherd-King, wore humility as His mantle. His greatness was revealed through service, not status.