Devarim Rabah (Nitzavim): They tell an Atzel, go to another city to learn Torah! He says, "Ari Bein ha'Rechovos." They tell him, there is a Chacham in your city (go to learn from him)! He says, "Ari va'Chutz" (14). They tell him, the Chacham is close to you - go learn from him! He says, "b'Soch ha'Rechovos Eratze'ach" (22:13). They tell him, he is in the house! He says, if I go, I will find the door locked; I will need to return. They tell him, the door is open - "ha'Deles Tisov Al Tzirah" (26:14)! In the end, he does not know what to answer. He says, whether the door is open or locked, I want to sleep a bit more - "Ad Masai Atzel Tishkav" (6:9). Mesilas Yesharim (Perek 9) - the fear does not cause him to be lazy. Rather, laziness causes him to fear.

Malbim: An Atzel, amidst his laziness, will come to this lowly Midah of Chacham b'Einav. This is worse than a Kesil. Chachmah needs Zerizus and great Avodah. An Atzel who slackens from it will come to be Chacham b'Einav. He will think that all his deeds are with Chachmah, and he need not seek the laws of Chachmah from Chachamim.

Malbim: Shachal is big; Ari is small. If he will seek exalted Chachmos that are not common, e.g. Ma'ase Bereishis and Ma'ase Merkavah, he will say that a Shachal will tear him (make him a heretic). Also to seek common Divrei Chachmah, he is concerned lest an Ari tear him.