From katanusso ('to pierce/sting'). Katanuxis originally meant 'a pricking/piercing' that produces stunned stupor β a state of spiritual numbness or stupefaction. Paul quotes Isaiah 29:10 using this word.
Romans 11:8 quotes Isaiah 29:10: 'God hath given them the spirit of slumber (katanuxis).' This divine judicial hardening β paradoxically β serves redemptive purposes. Israel's partial hardening made way for the fullness of the Gentiles to come in, after which 'all Israel shall be saved.' Katanuxis warns of the terrifying possibility of a heart so resistant to the Spirit that God confirms it in its numbness. It stands as the opposite of the pricking of heart (katanusso) in Acts 2:37, when the crowd was 'cut to the heart' under Peter's Pentecost sermon. The Spirit either pierces to life or confirms the numbing. Every sermon, every Scripture reading, is a kairos moment.