What is "Rom Einayim"?
Rashi: It is haughtiness.
Malbim: It is haughtiness about investigative Sechel. He thinks that he understands everything, and he decides matters about human Sechel and what is after nature. From this he comes to heresy and denial of Elokus.
What is "Rechav Lev"?
Rashi: It is wanting to fulfill desires of the heart.
Malbim: It is a heart that desires without limit.
Why is "Nir Resha'im Chatas"?
Rashi: Their plowing and intents are their sin.
R. Yonah, Sha'arei Teshuvah 1:27: It is as if it says v'Chatas. Also in "Shemesh Yare'ach" (Chabakuk 3:11, the prefix Vov is omitted). Pride is the plowed field of Resha'im. From it their sins multiply, just like crops increase due to a plowed field. Amidst their pride they pursue Aniyim - "b'Ga'avas Rasha Yidlak Oni" (Tehilim 10:2). They make people better than themselves be submissive to them, and impose fear on people. One who does so descends to Gehinom and is judged there for generations (Rosh Hashanah 17a). They speak Leshon ha'Ra and forget Hashem - "v'Ram Levavecha v'Shachachta" (Devarim 8:14). Aside from causing awesome sins, pride itself is a sin, and the proud are despised in front of Hashem - "To'avas Hashem Kol Gevah Lev" (16:5). Preparing the heart for Teshuvah is compared to a plowed field - "Niru Lachem Nir
R. Yonah: It says "ha'Chol ha'Yom Yacharosh ha'Choresh Lizro'a Yefatach vi'Ysaded Admaso" (Yeshayah 28:24). Does one plow forever?! He plows, and then seeds! "Ha'Lo Im Shivah Faneha v'Hefitz Ketzach v'Chamon Yizrok" (ibid. 25). Afterwards he hopes for rain to water the field, "v'Yisru la'Mishpat Elokav Yorenu" (ibid. 26). The Nevi'im rebuke you every day. They do not cease to rebuke and subdue your hearts, and you do not fix your deeds after rebuke! This is like one who always plows, and does not seed afterwards.