Why does it say "va'Amartem Al Mah"?
Radak: If you will ask, will Hashem not accept our Minchah due to our wives?
Malbim: Why is this sin so great?
What does Hashem testify between you and the wife of your youth?
Radak: You do not love her. Your heart is not with her - "Bagadta Bah"!
Malbim: You betrothed her with Chupah and Kidushin in front of Him. He was the witness, and now He warns you that you betrayed her and transgressed your tie to her.
What do we learn from "v'Hi Chavertecha"?
Radak #1: She was your companion from your youth.
Radak #2: She is your companion, even if she is not the wife of your youth. When she is the wife of your youth, all the more so you should love her more and not despise her - "v'Eshes Ne'urim Ki Sima'es" (Yeshayah 54:6).
Malbim: She did not betray you via quarrels.
Why does it add "v'Eshes Brisecha"?
Radak: You made a Bris between you and her when you married her, to be the wife of your youth, or she is not the wife of your youth, and you marry in addition to her another wife, a Nochris? This is a great betrayal. If the latter were a Yisraelis - this is normal, to marry another wife and have many wives. To take a Nochris is a great evil. He shows that the Nochris is a mistress like her, or more than her. It is proper that your wives cry due to you!
Malbim: She did not betray you via Zenus, which is Me'ilah in the Bris of marriage.
