The holy Quran has used the most appropriate terminology for scholars who do not practice what they preach, in one place likened them to dogs, as is mentioned in Ayah 176 of Surah Al-Aa’raf:

“If it had been God’s Will, God could have used these signs to raise him high, but instead he clung to the earth and followed his own desires; he was like a dog that pants with a lolling tongue whether you drive it away or leave it alone. Such is the image of those who reject God’s signs. Tell them the story so that they may reflect.”

From many of narrations and words of commentators it is concluded that this Ayah points to a man by the name of Bal’am Ba’oora who used to live at the time of Prophet Moses (AS). He was one of the famous scholars of Bani Israel and even Moses (AS) used him as a strong preacher and his status at one point was so high that his prayers were accepted by God. But as a result of his inclination towards Pharaoh and his promises,  Bal’am deviated from the truth and lost all his status to a level where he opposed Moses (AS) [1].

[1] Tafseer-e-Nemooneh, Vol. 7, Page 14.

Source: en.shafaqna.com