Because we don’t know the precise length of the cubit as it was being used before the Flood, we can only guess at Noah’s Ark’s true size. Based on a measure called the royal or long cubit, our estimate is that the Ark, which the Bible records as 300 cubits long, was over 500 feet in length.
One thing we don’t have to guess at is the need for some type of internal lighting. Noah was told “a window shalt thou make to the ark, and in a cubit shalt thou finish it above” (Genesis 6:16). Was this window for light, ventilation, or both?
Here’s the challenge. The Ark had three decks, so how could a window on the roof illuminate the two decks below? Let’s put on our Sherlock Holmesian deerstalker caps, because buried within the verse above is a clue.
Concerning the Ark, Genesis mentions windows only twice. The second reference is in Genesis 8:6. “
Noah opened the window of the Ark which he made.” Here’s where it gets interesting. In this verse, the Holy Spirit inspired the use of the word challon, “a window.” In the first reference, however, He used tsohar, “a light.” Tsohar comes from the Hebrew root tsahar, “to glisten.”
Did God perhaps instruct Noah to build “a light that glistened”?
Of the 24 times tsohar is used in the Old Testament, it is translated “window” only once. The 23 other occurrences refer to “noon” or “the noonday sun.”
How did Noah illuminate the Ark? We won’t know that, unless the mighty ship could still be found. (It’s highly doubtful that even sections of the Ark will ever be found on volcanic Mt. Ararat, or where the Bible says the Ark landed—in the “mountains of Ararat.”)
An ancient Hebrew tradition says the tsohar was a very large pearl or gem that Noah hung in the rafters of the Ark, which powered itself and illuminated the Ark.* That’s highly speculative to consider, of course, but it is something we have come across in our research.