Smite with thine hand, etc. The outward gestures were to give a dramatic emphasis to the mingled indignation and sorrow with which the prophet was to utter his woe. A like action meets us in Ezekiel 21:12.
Instances of its use for other feelings meet us in Ezekiel 22:13; Numbers 24:10 (anger); Jeremiah 31:19 (shame).