Musar על עבודה זרה 36:12

This is the intent of Shlomo's warning: "do not mingle with those who make changes" (Prov.24:21). If a man claims to you: "a person's mind should always be associated with his fellow men" (Ketuvot 17a), reply to him, "this refers to human beings who act like human beings. Not human beings who act like animals." Shlomo warns further: "Go from before a foolish man" (Prov. 14:7). And King David said: "Fortunate is the man that walks not in the counsel of the wicked, nor stands in the way of sinners, nor sits in the seat of scoffers" (Ps. 1:1). Our sages expounded this: "If he walks, he will eventually stand. If he stood, he will eventually sit" (Avodah Zara 18b). And "I did not sit with men of falsehood, neither did I go with hypocrites. I have hated the congregation of evil-doers, and will not sit with the wicked" (Ps. 26:4-5).