Who is "Koretz Ayin Yiten Atzaves"?
Rashi: This is one who entices for evil via winking the eye.
R. Yonah: When his speaks with his colleague about matters Bein Adam l'Chavero, he winks and hints to others, or to himself, that he schemes to trick and defeat his colleague. He brings grief to himself, for his colleague fears and guards himself from him, and he does not succeed.
Malbim: Our verse gives two intermediaries between the opposites in verse 9 (one who believes, and goes on the straight path that they showed to him, and one who goes on the crooked path). The latter's action revealed [his fear]. Koretz Ayin goes on the straight path, but his eyes show that he looks also at the other path and seeks which is correct. Even though he is not damaged, for he goes on the straight path, he saddens himself, for he is unsure.
Why does it say "v'Evil Sefasayim Yilavet"?
R. Yonah: He is foolish to verbalize his intent. He is more foolish than one who winks! Below (12:16), it says "Evvil ba'Yom Yivada Kaso." Man's heart and secrets are revealed via three Midos - strategies and schemes, winking and gestures, and an Evvil reveals with his lips.
Malbim: He is unsure with his lips. Even though he does not look to seek the crooked path, for he relies on what they told him, and goes on the way of Chachmah in his heart, he is Evvil and unsure with his external lips (expresses doubts).
