The Hebrew word egroph denotes a closed fist. It appears in Isaiah 58 where God rebukes Israel for practicing fasting accompanied by strife and striking with the fist.
The single use of egroph in Scripture carries tremendous prophetic weight. God declares that striking with the fist while fasting is incompatible with true worship. Authentic devotion to God must produce ethical transformation. True religion loosens chains and feeds the hungry (Isaiah 58:6-7).