Star

 
כּוֹכָב Strong’s #3556 kokav

And he brought him forth abroad, and said, Look now toward heaven, and number the stars, if thou be able to number them: and he said unto him, So shall thy seed be.

Genesis 15:5

https://biblehub.com/hebrew/3556.htm

Of course we know that stars are extremely large balls of gas trillions and trillions of miles out in space, but how did the Ancient Hebrew perceive the stars? Reading the Bible must be from the Hebrew perspective, not ours. The Hebrews, being nomads, lived in black goat hair tents. The hair fabric had pinholes of light and when looking up at the tent roof, it looked just like the night sky. This is alluded to in Isaiah 40:22: God stretcheth out the heavens as a curtain, and spreadeth them out as a tent to dwell in.