Jeremiah 12:7 is a powerful statement from God expressing his deep sorrow and disappointment over the unfaithfulness of the people of Judah. Let's break down each phrase to understand its meaning:

"I have forsaken my house...": "My house" refers to the Temple in Jerusalem, which was considered God's dwelling place. Forsaking it means God has withdrawn his protection and presence from the Temple, leaving it vulnerable.

"...I have cast off my heritage...": "My heritage" refers to the land of Israel, which was given to the Israelites as their inheritance from God. Casting it off means God is about to allow the people to be exiled from their land. He is rejecting them as his chosen people because of their disobedience.

"...I have given the dearly beloved of my soul into the hand of her enemies.": "The dearly beloved of my soul" refers to the people of Judah, whom God deeply loved. Despite their unfaithfulness, they were still the object of his affection. Giving them into the hand of their enemies means God is allowing them to be conquered and oppressed by foreign nations (specifically Babylon). This is a consequence of their persistent idolatry and rejection of God's laws.

In essence, the verse is a lament from God expressing his grief and impending judgment on Judah. It highlights:

God's deep love for his people: Despite their sins, they are still "the dearly beloved of my soul."
God's sorrow at their unfaithfulness: The verse is filled with a sense of loss and rejection.
God's impending judgment: As a consequence of their sins, God is withdrawing his protection and allowing them to be conquered and exiled.
The severity of Judah's sin: God has reached the point where he feels compelled to abandon his "house" and "heritage."

This verse shows the tragic consequences of turning away from God and the profound pain it causes Him. It serves as a warning and an expression of divine sorrow and determination to administer justice.