because: Jeremiah 7:26, Jeremiah 17:23, Jeremiah 35:15-17; 2 Chronicles 36:16-17; Nehemiah 9:17, Nehemiah 9:29; Zechariah 7:11-14; Acts 7:51-52
hardened: This is a metaphor taken from unruly and unbroken oxen, who resist the yoke, and break and run away with their gears.
that they: Psalms 58:2-5