Genesis 6:15

Make the ark like this: 300 cubits long, 50 cubits wide, and 30 cubits high.

Genesis 7:20

The flood waters rose 15 cubits above the mountains.

Deuteronomy 3:11

Only King Og of Bashan remained from the remnants of the Rephaim. In fact, his bed was made of iron. It's in Rabbah of the Ammonites, isn't it? It was nine cubits long and four cubits wide."

Treasury of Scripture Knowledge

Summary

And this is the fashion which thou shalt make it of: The length of the ark shall be three hundred cubits, the breadth of it fifty cubits, and the height of it thirty cubits.

Bible References

Cubits

Genesis 7:20
The flood waters rose 15 cubits above the mountains.
Deuteronomy 3:11
Only King Og of Bashan remained from the remnants of the Rephaim. In fact, his bed was made of iron. It's in Rabbah of the Ammonites, isn't it? It was nine cubits long and four cubits wide."

International Standard Version Copyright © 1996-2008 by the ISV Foundation.