| Proverbs 18:19 | A brother offended [is harder to be won] than a strong city: and [their] contentions [are] like the bars of a castle. |
| Jeremiah 5:3 | O LORD, [are] not thine eyes upon the truth? thou hast stricken them, but they have not grieved; thou hast consumed them, [but] they have refused to receive correction: they have made their faces harder than a rock; they have refused to return. |
| Ezekiel 3:9 | As an adamant harder than flint have I made thy forehead: fear them not, neither be dismayed at their looks, though they [be] a rebellious house. |