Hate is only implied.
How could He have hated Esau, let alone before birth? That's not the God we think we know. We have to keep in mind that cultures differ in how they speak, which involves more than just the specific words they use. Different societies use different forms and figures of speech, as well. In that era, the love-hate phrasing is meant to show a contrast, not to imply that one side is looked at in some insulting way.
It helps to look at another example of the word "hate" in the New Testament. Jesus said this to those who were deciding about whether to follow Him or not: "If anyone comes to me and does not hate his own father and mother and wife and children and brothers and sisters, yes, and even his own life, he cannot be my disciple" (
Luke 14:26). Clearly, Jesus doesn't want us to carry bitter, angry feelings toward our fathers, mothers, wives, and children. After all, we are commanded in Scripture to honor our parents, love our wives, and to raise our children wisely. In this case, the word "hate" is about comparison. Jesus wanted disciples who were so deeply committed to Him that their love for their family members looked like hate by comparison.
The same idea is at work in God's use of these contrasting words in Malachi and quoted by Paul here. God's act of love for Jacob, in choosing to give to him the covenant promises, was well beyond His actions towards Esau, in declaring that Esau would serve Jacob. There is a strong contrast there: one is clearly being given the preferred treatment, the other is not. Using dramatic, contrast-enhancing language, it can be said that one was "loved" and the other "hated."
BibleRef