Question: "What does it mean to profane the covenant (Malachi 2:10)?"
Answer: In Malachi 2:10 the prophet asks, “Have we not all one Father? Did not one God create us? Why do we profane the covenant of our fathers by breaking faith with one another?” The obvious reference in this verse is the covenant made between the Lord and the people of Israel at Sinai. To profane something is to defile it or treat it contemptuously. Judah had broken the Mosaic Law, thus “profaning,” or showing contempt for, the covenant.
The Jewish people had one “Father” in that their nation had been created by God (Deuteronomy 32:6). Yet they had become faithless to one another. This description likely includes incivility toward each other (in violation of Leviticus 19:18) as well as unfaithfulness in their marriage relationships—a discussion of marriage and divorce follows in the next verses. Malachi condemns intermarriage with idolaters (Malachi 2:11) as well as divorce in general (2:13-16).
Malachi 2:11 speaks of mixed marriages between Israel and its non-Jewish neighbors (the issue was not racial but spiritual—God’s people who married idolaters were also engaging in false worship). The Mosaic Law explicitly taught against this: “Do not intermarry with them. Do not give your daughters to their sons or take their daughters for your sons, for they will turn your sons away from following me to serve other gods” (Deuteronomy 7:3-4; also see Exodus 34:15-16). Idolatry caused by intermarriage was a common problem in Judah. Even King Solomon married those outside of Israel as part of his alliances with other nations, and his heart was turned from the Lord (1 Kings 11:1-8). Ezra and Nehemiah, contemporaries of Malachi, also recorded dealing with such marriages (Ezra 9:2; Nehemiah 10:30).
A New Testament principle regarding marriage also emphasizes spiritual purity. Second Corinthians 6:14-15 teaches, “Do not be unequally yoked with unbelievers. . . . What portion does a believer share with an unbeliever?” (see also 1 Corinthians 7:39).
Malachi calls Judah’s sin the profaning of their covenant with God. In breaking their marriage covenants with their spouses, God’s people showed disrespect for the Mosaic Covenant. God’s word to Malachi was the same as His word to Joshua centuries before: “Israel has sinned; they have violated my covenant, which I commanded them to keep” (Joshua 7:11).