The account of the creation of the sun and moon on the fourth day is described in the book of Genesis in the Bible. According to the biblical narrative, before the creation of the sun and moon, the concept of day and night still existed. However, the specific mechanism by which light and darkness were separated is not explicitly mentioned in the text.
In Genesis 1:3-5 (New International Version), it is stated:
"And God said, 'Let there be light,' and there was light. God saw that the light was good, and he separated the light from the darkness. God called the light 'day,' and the darkness he called 'night.' And there was evening, and there was morning—the first day."
From this account, it is clear that there was a distinction between light and darkness, resulting in periods of day and night, even before the creation of the sun and moon. The exact nature of this light source is not explained in the text, and it is a topic of theological interpretation and discussion.
Different interpretations have been proposed, including the idea that God provided a supernatural or divine light source before the sun and moon were created. Others suggest that the initial light may have been diffuse or indirect, and the creation of the sun and moon brought about a more familiar and predictable cycle of day and night.
It's important to note that the book of Genesis is a religious text containing symbolic and theological accounts of creation, and different religious traditions may interpret these passages in various ways. Scientific explanations of the origin of light and the formation of day and night are based on empirical evidence and fall within the realm of scientific inquiry, distinct from religious texts.