Charles Ellicott Commentary Malachi 1:12

"But ye profane it, in that ye say, The table of Jehovah is polluted, and the fruit thereof, even its food, is contemptible." — Malachi 1:12 (ASV)

But you have. —Better, but you profane it —namely, my name (Malachi 1:11). The word “it” is said by Jewish tradition to be a euphemism for “me.” The present contemptuous conduct of God’s priests is contrasted with the prophesied reverence of heathen nations.

Fruit ... meat, denote the same as bread of Malachi 1:7. They show that they think it contemptible by not taking the trouble to offer such things as are prescribed by the Law.