1)
What does the Pasuk mean when it writes "ve'Nod'ah ha'Chatas"? Is it not obvious that they cannot bring a Korban before they know that they have sinned?
1.
Ramban #1, Moshav Zekenim #1: It is a manner of speech, as if to say 'When they know that they have sinned... '. 1
2.
Ramban #2, Moshav Zekenim #2: To teach us that they are only Chayav if they know for sure that they have sinned - but not on a Safek. 2
3.
Ramban #3: To teach us that, not only must they know that they ruled incorrectly, but also exactly what their mistake was. 3
