The sun and the moon are too clear, what does it mean to stay in obsidian?

The sun and the moon are very bright and clear, and stars and purple flowers are hanging in the sky. This is an ancient astronomical observation term in China. Among them, "the sun and the moon are too clear" means the weather is sunny and sunny; "Liesu Yao" refers to 28 fixed constellations, and "Wei Zi" is one of the seven places in Xuanwu, also known as North Xuanwu.