Abominations - The mixed marriages had prevented that complete separation of the people of God from the idolatrous rites, or “abominations,” which the Law required, and which was necessary for purity of religion. See 1 Kings 11:2 note.
Related Commentaries of Ezra 9:1
Ezra 9:1
1 Now when these things were done, the princes came to me, saying, The people of Israel, and the priests, and the Levites, have not separated themselves from the people of the lands, doing according to their abominations, even of the Canaanites, the Hittites, the Perizzites, the Jebusites, the Ammonites, the Moabites, the Egyptians, and the Amorites.