Judah has been unfaithful (Mal 2:11-2:12)

“Judah has been faithless.

An abomination

Has been committed

In Israel,

As well as in Jerusalem.

Judah has profaned

The sanctuary of Yahweh

That he loves.

He has married

The daughter of a foreign god.

May Yahweh cut off

From the tents of Jacob

Anyone who does this!

May Yahweh cut off

Anyone who witnesses,

Who answers,

Who brings an offering

To Yahweh of hosts!”

Yahweh, via Malachi, noted that Judah had not been faithful.  There was an abomination in Jerusalem itself.  Judah had profaned the sanctuary of Yahweh.  Judah had married the daughter of a foreign god.  Perhaps this indicates a non-Jewish woman.  Thus, Yahweh was going to cut them off from the tents of Jacob.  Anyone involved in any kind of false worship of a foreign god would be cut off from being a witness or bringing offerings to Yahweh.  They should be excommunicated.

The worship on the mountain tops (Hos 4:13-4:13)

“They sacrifice

On the tops

Of the mountains.

They make offerings

Upon the hills.

They make offerings

Under the oak trees,

Under the poplar trees,

Under the terebinth trees.

Their shade is good.

Therefore,

Your daughters

Play the prostitute.

Your daughters-in-law

Commit adultery.”

The Israelites were sacrificing to the various Canaanite gods on the tops of the mountains. They were making offerings on the hills. They preferred to make these offerings under the various trees, the oak, the poplar, and the terebinth, because the shade of those trees was good. Thus, their daughters became prostitutes, while their daughters-in-law committed adultery. Clearly, they were unfaithful to Yahweh.