A HARDENING — and the word is medical before it is moral: pōros is a callus, the bony deposit that forms over a healed fracture, or the stone-like matter in a joint. ⚠ So Mark 3:5, 'grieved at the pōrōsis of their heart', is not describing stubbornness as a mood but tissue that has stopped being able to feel. And the diagnosis is not reserved for opponents: Mark turns the same root on the DISCIPLES twice, after the loaves (6:52) and again in the boat (8:17), which is the sort of thing this Gospel does without comment. Paul takes the noun up at Romans 11:25 for a hardening 'in part' that is temporary, and at Ephesians 4:18. KJV reads 'hardness', which is right but has lost the physical picture. → first discussed at Mark 3:5