Thomas Aquinas Commentary Jeremiah 6:20-21

"To what purpose cometh there to me frankincense from Sheba, and the sweet cane from a far country? your burnt-offerings are not acceptable, nor your sacrifices pleasing unto me. Therefore thus saith Jehovah, Behold, I will lay stumbling-blocks before this people; and the fathers and the sons together shall stumble against them; the neighbor and his friend shall perish." — Jeremiah 6:20-21 (ASV)

Here he discusses the abuse of sacred things; since they were polluted with sins, they presumed to offer sacrifices to God, which, for this reason, were not accepted; concerning this, he makes two points.

1. First, he proves their guilt from the fact that their sacrifices were not accepted. Regarding the things offered on the altar of incense: why do you bring me the frankincense of Sheba, the region from which frankincense comes;Biblical Sheba was almost certainly the kingdom of Saba centered around the oasis of Marib in present day Yemen. calamus, cinnamon,Heb. קָנֶה הַטּוֹב: the goodly reed. Most likely acorus calamus, sweet flag, an aromatic marsh plant. which was put in the incense whose composition is given in Exodus 30:34;Neither calamus nor cinnamon are listed as among the ingredients in the incense to be burned in the Tabernacle in Exodus 30:34; they are both, however, used in the anointing oil, described in Exodus 30:23. from a distant land, that is, from India. He who is mindful of frankincense is as one who blesses an idol (Isaiah 66:3).

   Regarding the altar of burnt offerings: your holocausts. I have refused your holocausts of rams, and the fat of your fattened beasts, and the blood of your calves, lambs and goats (Isaiah 1:11).

2. Second, he speaks of their punishment. Therefore, thus says the Lord. The people will oppress each other, man against man and each one against his neighbor (Isaiah 3:5).