V.2-5 One man suggests a very strong and difficult remedy. A full confession of their guilt, and a willingness to separate from that which was so displeasing to the Lord.
V.3 The wives, and the children were to be put away. This was according to the law, for they were unclean. In 1 Corinthians 7:14, notice the contrast between the law and the grace of God. In 1 Corinthians 7 neither the wife nor the children need to be put away if the husband becomes a believer. It is still wrong and disobedient to marry an unbeliever. A believer can pray to the Lord that the partner and the children may be saved.
V.9-10 Ezra first explains their sin, then urges them to confess it and then holds them responsible to separate themselves. Confession is one thing, but there must be a turning away from the sin itself. There would have been no “strange wives” if there had been proper separation from the people of the land.
V.18 The actual list of those who were guilty, and it begins with the priests! They were that much more responsible because of their position and their influence.