the Lord God. Hebrew. Adonai Jehovah. See note on Ezekiel 2:4.
Behold. Figure of speech Asterismos. App-6.
the great dragon. the great crocodile, to which Egypt was likened on Roman coins. Compare Isaiah 51:9, where "Rehab" is used of Egypt (Isaiah 30:7).
My river. the Nile.
I have made it. Referring probably to the artificial system of canals and water-ways.