Why does it say "Ein Ra"?
Rashi: Is this not a bad thing?
Radak: You say that it is good to offer a blind Seh, for the Shulchan (Mizbe'ach) is disgraced, You should have told those who bring it, it is bad to offer this, like the Torah says "Averes Oh Shavur... Lo Sakrivu Eleh la'Shem" (Vayikra 22:22). You show favoritism to those who bring it, and accept the inferior, and say that it is not bad.
Malbim: This is "Lechem Megu'al" (7) - a Ba'al Mum will not be accepted for a Korban.
Why are lame and ill taught separately from blind?
Malbim: Lame and ill are worse - the blemish is more overt.
What do we learn from "Hakrivehu Na l'Fechasecha"?
Radak: How can you say that it is not bad to offer it in front of Me?! If you would offer it to your human officer, would he be pleased with this gift, or favor you due to it, if you request something from him? He will hate you for it, and be angry at you! Pechasecha is like "Pachas Yehudah" (Chagai 1:14). He is a governor, like the Targum says.
Malbim: If you would give such a gift to Pachas Yehudah, a person, would he be pleased with this gift, or favor you? Even if you are someone proper to favor, he would cease to favor you amidst anger over this disgrace.
