‘And Cush begat Nimrod. He began to be a mighty one on the earth. He was a mighty warrior (hunter) before Yahweh (i.e. even in the Yahweh's eyes); wherefore it is said “Like Nimrod a mighty warrior before Yahweh”.'
Here we begin to see some of the complications facing us in identifying some of these peoples. Nimrod was clearly, in pre-history, a great warrior who left his homeland seeking conquests and established great cities. Thus the descendants of Cush become connected with Mesopotamia.
This need not necessarily mean that the Cassites were all directly descended from Cush. It could mean that Nimrod, possibly with a small but powerful band of warriors, conquered the people who became known as Cassites in a similar way to that in which the Philistines became overlord of some Canaanites and gave them their name.
The reference to ‘a hunter' probably indicates his warrior status as a hunter of men. But ancient kings did boast excessively about their prowess in the hunt and he may actually have been remembered as an exceptional hunter. In Micah 5:6, Assyria is described as ‘the land of Nimrod' confirming the above connections.
“Wherefore it is said -”. This probably indicates a quotation from an epic passed down through the ages (compare Numbers 21:14). It is possible that the writer had access to ancient records about Nimrod and his activities. Alternately it may have been a well known proverb.
“Before Yahweh”. Compare Jonah 3:3 where Nineveh is described as ‘a city great to God'. The idea is that even Yahweh God sees them as great. It represents a superlative.