God has come to Mount Zion in splendor to make his case against Israel. He will now testify against them.
Yes, they were sacrificing animals as prescribed in the covenant law given through Moses. The covenant the Lord God had with Israel was two-sided. He would be their God and they would live according to the good way people were originally designed to live. This is the sum of the covenant. Their part included offering sacrifices to him. This they were doing.
However, their intent was wrong. The reason they offered was wrong. They began believing that God needed the animals they were sacrificing. The Israelites believed the Lord God needed to eat animals for sustenance. This was a wrong concept and understanding of God and the reason they were to present offerings to him. The animal sacrifice system was not for God’s benefit but for their benefit. Mankind has a deep need to offer to God. It is good and it is right.
Sacrifice and offering are the physical elements that worshipers bring to God to express devotion, thanksgiving, and the need for forgiveness to God. Tithing is an offering that was before, during, and after the sacrifice system presented through Moses was given as part of the covenant Israel had with the Lord God. Noah made an offering. Abraham, Issac, and Jacob made offerings.
Jesus’ teachings included offering. The cleansing of the Temple (John 2) came about because people were selling animals and birds for the various sacrifices within the Temple precincts. These people had allowed the “business” of sacrifice to overwhelm the spiritual nature of the offerings.
God sacrifices too. He sacrificed his Son, Jesus for the redemption of my soul. In fact, all the human sacrifices in the law given through Moses point to God sacrificing his one and only Son. In this is the deep need for sacrifice. Sacrifice is part of a loving relationship with another.