“exceedingly, yes, exceedingly.” By repeating the word “exceedingly” (or, “greatly”), the Hebrew text emphasizes the way the water covered the earth. Noah’s Flood was not a local event, as some people would have us believe. The Bible is clear that the water covered all of the earth that was under heaven. Besides, if the flood was local, God would have just had Noah and his family move away. That would have taken much less time and effort than building the ark.
The verse gets emphasis from the figure of speech epizeuxis. If a word is repeated in a sentence in exactly the same form, as it is in the Hebrew text here, it is the figure of speech epizeuxis (Bullinger, Figures of Speech Used in the Bible; Oxford English Dictionary). In fact, if the words are repeated right next to each other as these are, Bullinger refers to it as a subset of epizeuxis called geminatio. If the root word is repeated but the word is inflected differently, that is the figure of speech polyptoton. [For more on polyptoton in the Bible, see commentary on Genesis 2:16].