Genesis 6:15

This is how you shall make it. The length of the ship will be three hundred cubits, its breadth fifty cubits, and its height thirty cubits.

Genesis 7:20

The waters prevailed fifteen cubits upward, and the mountains were covered.

Deuteronomy 3:11

(For only Og king of Bashan remained of the remnant of the Rephaim; behold, his bedstead was a bedstead of iron; isn't it in Rabbah of the children of Ammon? nine cubits was its length, and four cubits its breadth, after the cubit of a man.)

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 waters prevailed fifteen cubits upward, and the mountains were covered.
Deuteronomy 3:11
(For only Og king of Bashan remained of the remnant of the Rephaim; behold, his bedstead was a bedstead of iron; isn't it in Rabbah of the children of Ammon? nine cubits was its length, and four cubits its breadth, after the cubit of a man.)