Malachi 1:8 And if ye offer the blind for sacrifice, is it not evil? And if ye offer the lame and sick, is it not evil? Offer it now unto thy governor; Will he be pleased with thee, or accept thy person? saith the LORD of hosts.
The people didn’t respect God. They gave God things that were unusable in other places and for other purposes. They were giving God things of no value. They needed a place to dump their used and abused things and so they gave them to God.
The Temple was the GoodWill store of their day. Not the place to get gently used things but the place to give things that you would never use to pay your taxes or gain favor with someone in business etc.
Isn’t that often what happens with our God today. We give Him the time we have left over! We give Him money if we have any to spare or what we might give a beggar. We take care of ourselves first and if we have anything we might give it.
Our house, our hobby, our things come first and then we move on to what we might give to God.
God is offended by this attitude. If He is truly God then He deserves better treatment than that!