To što oni nisu vjerovali u ajete Allahove i ubijali vjerovjesnike bez prava; to što nisu slušali, a prevršivali su.
That was because they used to disbelieve the Ayat (proofs, evidences, verses, lessons, signs, revelations, etc.) of Allah and killed the Prophets wrongfully. That was because they disobeyed and used to transgress the bounds (in their disobedience to Allah, i.e. commit crimes and sins).