Albert Barnes Commentary Malachi 1:13

"Ye say also, Behold, what a weariness is it! and ye have snuffed at it, saith Jehovah of hosts; and ye have brought that which was taken by violence, and the lame, and the sick; thus ye bring the offering: should I accept this at your hand? saith Jehovah." — Malachi 1:13 (ASV)

What a weariness! - What an onerous service it is! The service of God is its own reward. If not, it becomes a greater toil, with less reward from this earth, than the things of this earth. Our only choice is between love and weariness.

And you have snuffed (puffed) at it, that is, at the altar, as a thing contemptible.

“You have brought that which was taken by violence.” In despising any positive law of God, they despised the Lawgiver; and so, from contempt of the ceremonial law, they went on to break the moral law.

It would indeed be a mockery of God to break a law by which He bound man to man, and from that action to seek to appease Him. Yet in rough times, people, even in Christianity, have sought to make things right with their souls by giving to the poor a portion of what they had taken from the rich.

“God,” it was said to such a person, “rejects the gifts obtained by violence and robbery. He loves mercy, justice and humanity, and by the lovers of these only will He be worshiped” . “He that sacrificeth of a thing wrongfully gotten, his offering is ridiculous, and the gifts of unjust men are not accepted. The Most High is not pleased with the offerings of the wicked, neither is He pacified for sin by the multitude of sacrifices. Whoso bringeth an offering of the goods of the poor doeth as one that killeth the son before the father’s eyes.”