Marriage is a supposed to be a picture of Christ and his church. Christ laid down his life for his followers as men are supposed to lay down their lives for their wives. This teaching comes straight from Ephesians, but that doesn't mean God didn't expect Israelites before Jesus to act like this as well. Unfortunately In Malachi 2 we find out that the men of Israel have left the wives they took in front of God and have made new marriages with women of other nations and bowed down to their Gods. God calls out the violence and damage they have done to themselves and the women of Israel by abandoning them for other women, much like they have abandoned God for false idols.