Then God set them in the expanse of the heavens to give light on the earth,

Genesis 1:17 — Modern English Version (Thinline Edition.; Lake Mary, FL: Passio, 2014)

God set or placed them in the expanse. This is the Hebrew word yitten. The meaning of the word conveys something that is given but can also be used as something loaned with an expectation of interest.

This speaks to the anthropic principle of creation. Things are made just so for human existence. This includes the sun, moon, and stars. They are set, just so, in place.

Furthermore, the possible idea of these being loaned is intriguing. We know there will be no more use for the sun, not as it seems to be purposed for.

The city has no need of sun or moon to shine in it, for the glory of God is its light, and its lamp is the Lamb.

Revelation 21:23 — Modern English Version (Thinline Edition.; Lake Mary, FL: Passio, 2014)

The purpose of the sun is temporary much like a loan. It is also expected to give interest. This it does, serving as the main energy source for the plants that would be the food for humans and other creatures.

In this way, the creation is giving us an agrarian typology of planting for harvest. We’ve read the texts that a seed is expected to produce more than it is when planted. In the same way, the sun is expected to be the impetus to produce a harvest of souls.

I looked. And there was a white cloud, and on the cloud sat One like a Son of Man, having on his head a golden crown, and in His hand a sharp sickle. Then another angel came out of the temple, crying with a loud voice to Him who sat on the cloud, “Thrust in Your sickle and reap. The time has come for You to reap, for the harvest of the earth is ripe.” So He who sat on the cloud thrust His sickle on the earth, and the earth was harvested.

Revelation 14:14–16 — Modern English Version (Thinline Edition.; Lake Mary, FL: Passio, 2014)