Why does it say "Magishim... Lechem Megu'al ba'Meh Ge'alnucha"?
Rashi: If you will say, how did we repulse You? Did we make repulsive the food of Your Mizbe'ach? I answer, via this You repulsed Me - you say, "Shulchan Hashem Nivzeh Hu." They disgraced to trade Menachos and Kodshim. Since we may not trade a Minchah for a Minchah, and a Zevach for a Zevach, it is a toil to divide each Minchah for a k'Zayis or the size of a bean that each one receives.
Radak: Lechem is Korban, like "Es Lechem Elokecha", "Lechem Isheh" (Vayikra 21:21, 3:11), "Korbani Lachmi" (Bamidbar 28:2). Megu'al is despised and filthy - lame, blind and ill (8). How can you say ba'Meh Ge'alnucha? If you sully the blood of My Mizbe'ach, you repulse Me!
Malbim: Amidst honor and love of Hashem, you should not disgrace My name, for this is the opposite of honor. Due to fear you should not offer despised food - you should fear punishment!
Why does it say "va'Amartem" and "be'Amarchem"?
Radak (6): The latter answers how they disgrace His name (6). Beforehand, it mentions their repulsive act - they offer...
Malbim: You ask, how did we disgrace Your name? How did we repulse You? You deny doing do.
What is "Shulchan Hashem"?
Radak, Malbim: It is the Mizbe'ach. Also Yechezkel said "Zeh ha'Shulchan Asher Lifnei Hashem" (41:22).
Why do they say "Nivzeh Hu"?
Radak, Malbim: They offer blood and Chelev, which are disgraced. They do not put to their hearts why Hashem commanded to offer blood and Chelev!
