Radak: I know that I sinned; I do not deny it, like Kayin said "Lo Yadati" (Bereishis 4:9).
2.
Malbim: This corresponds to "Kabeseni me'Avoni" (verse 4). The stain is removed from the Nefesh, since it no longer denies the Mitzvah.
2)
What is the meaning of "v'Chatasi Negdi Tamid"?
1.
Rashi: I constantly regret and worry about my sin. It is as if it is always in front of me. Sha'arei Teshuvah (1:48) - it is proper for one who sinned to always remember it and never forget it.
2.
Radak: I constantly regret and am pained over this sin.
3.
Malbim: This corresponds to "ume'Chatasi Tahareni" (verse 4). Since my sin was only against You (verse 6), Teshuvah suffices for Taharah.
