The people challenged God to hurry and act. They wanted him to prove that he truly exists and rules the world.
The verb hurry translates two Hebrew verbs:
maher (“be quick”)
khush (“be speedy”)
These same words appear in the name Maher-shalal-hash-baz (Isaiah 8:1).
God had revealed his plan to Isaiah. The people did not understand that God’s purposes would turn against them. Instead of bringing the kind of help they expected, God’s action would bring judgment.