لَوْلَا يَنْهَاهُمُ الرَّبَّانِيُّونَ وَالَاحْبَارُ عَن قَوْلِهِمُ الاِثْمَ وَأَكْلِهِمُ السُّحْتَ
Why do not the Rabbaniyyun and the Ahbar forbid them from uttering sinful words and from eating illegal things.
meaning why don't the Rabbaniyyun and the Ahbar forbid them from this evil!
The Rabbaniyyun are the scholars who are in positions of authority, while the Ahbar are the regular scholars.
لَبِيْسَ مَا كَانُواْ يَصْنَعُونَ
Evil indeed is that which they have been performing.
Ali bin Abi Talhah reported from Ibn Abbas,
referring to the Rabbaniyyun, because they abandoned forbidding evil.
Ibn Jarir recorded that Ibn Abbas said,
"There is no Ayah in the Qur'an that has more severe admonition than this Ayah,
(Why do not the Rabbaniyyun and the Ahbar forbid them from uttering sinful words and from eating illegal things. Evil indeed is that which they have been performing)."
Ibn Abi Hatim recorded that Yahya bin Ya`mar said,"
Ali bin Abi Talib once gave a speech, which he started by praising Allah and thanking Him.
He then said, `O people! Those who were before you were destroyed because they committed sins and the Rabbaniyyun and Ahbar did not forbid them from evil. When they persisted in sin, they were overcome by punishment. Therefore, enjoin righteousness and forbid evil before what they suffered also strikes you. Know that enjoining righteousness and forbidding evil does not reduce the provision or shorten the term of life."
Imam Ahmad recorded that Jarir said that the Messenger of Allah said,
مَا مِنْ قَوْمٍ يَكُونُ بَيْنَ أَظْهُرِهِمْ مَنْ يَعْمَلُ بِالْمَعَاصِي هُمْ أَعَزُّ مِنْهُ وَأَمْنَعُ وَلَمْ يُغَيِّرُوا إِلاَّ أَصَابَهُمُ اللهُ مِنْهُ بِعَذَاب
There is no people among whom there are those who commit sins, while the rest are more powerful and mightier than the sinners, yet they do not stop them, but Allah will send a punishment upon them.
Ahmad was alone with this wording.
Abu Dawud recorded it, but in his narration Jarir said,
"I heard the Messenger of Allah saying,
مَا مِنْ رَجُلٍ يَكُونُ فِي قَوْمٍ يُعْمَلُ فِيهِمْ بِالْمَعَاصِي يَقْدِرُونَ أَنْ يُغَيِّرُوا عَلَيْهِ فَلَا يُغَيِّرُوا إِلاَّ أَصَابَهُمُ اللهُ بِعِقَابٍ قَبْلَ أَنْ يَمُوتُوا
There is no one who resides among people committing evil among them, and they do not stop him though they are able to do so, but Allah will punish them (all) before they die."
Ibn Majah also recorded this Hadith