Why does it say "ha'Ma'aras Paritzim"?
Rashi: This is said in astonishment. Radak - this doubles your sin. After doing what I forbade, you are brazen to come to Me [and ask to be saved]! It is wantonness, brazenness, hard-heartedness, a great rebellion and vexing.
Why is it called a cave?
Radak: Wanton sinners often gather outside the city in a cave to hide from people.
Malbim: Just like wanton sinners hide in a cave, so you want to conceal your deeds via the Bayis.
Why does it say "b'Eineichem"?
Malbim: If you see someone bow to his G-d in the Bayis, you think that he is a total Tzadik, and his abominations are hidden from your eyes.
Why does it say "Hinei Ra'isi"?
Rashi: [I know that] so it is in your eyes.
Radak: Do not think that I do not see your evil thoughts. I am not like a person, that others can deceive him, and show what is not in his heart. I see your hearts, that when you come to Me, your gearts are not to me. Rather, you intend to do more of your prior abominations.
Malbim: Even if things are hidden from your eyes, for you do not see hidden matters, I see hidden matters.