Psalm 115:16, "The heavens are the heavens of Yahweh; but the earth has he given to the children of men," expresses a fundamental idea about God's relationship to creation and humanity's role in the world. Here's a breakdown of its meaning:

"The heavens are the heavens of Yahweh": This emphasizes God's absolute sovereignty and ownership over the celestial realm, the heavens. It's His domain, His territory, His sphere of influence. Yahweh is the Hebrew name for God.

"but the earth has he given to the children of men": In contrast to the heavens, God has entrusted the earth to humanity. This gift implies a responsibility. God has delegated authority and stewardship over the earth to humankind.

Key implications and interpretations:

Stewardship: Humans are seen as stewards or caretakers of the earth. We are meant to manage, cultivate, and care for it in a way that reflects God's will and benefits all. This perspective emphasizes responsibility towards the environment and each other.
Domain and Responsibility: This verse doesn't necessarily imply absolute, unchecked dominion. Rather, it suggests a delegated authority accompanied by responsibility. We are meant to use the earth's resources wisely and justly.
Divine Authority vs. Human Agency: The verse highlights the balance between God's ultimate authority and human agency. God has given us a certain sphere of influence and freedom, but we are still accountable to Him for how we use it.
Relationship: It underscores the relationship between the divine and the human, and how this relationship should affect how we treat one another, and the world around us.

In essence, Psalm 115:16 articulates a worldview where God reigns supreme in the heavens, but humanity has been granted a significant role and responsibility on Earth. We are called to be good stewards of the planet, acting in accordance with God's will and principles.