Matthew Poole and continuators on Exodus 7:9

9 When Pharaoh shall speak unto you, saying, Shew a miracle for you: then thou shalt say unto Aaron , Take thy rod , and cast it before Pharaoh, and it shall become a serpent .

By whose hands this and other miracles were to be done, and not by Moses immediately, partly to take off the suspition that these miracles were wrought by some magical artifice of Moses; and partly for the greater honour of Moses, that he might be, what God had said, ver. 1. a God to Pharaoh, who not onely could work wonders himself, but also give power to others to do so.

The same rod is called the rod of God, and of Moses, and of Aaron, here and ver. 12. because it was appointed and as it were consecrated by God, and used both by Moses and Aaron in their great works. And this rod Moses ordinarily held in his hand, and delivered it to Aaron upon occasion, for the execution of his commands.

Heb. A dragon, which is a great serpent: Others, a Crocodile, to whose jaws he had exposed the Israelitish Infants.

Marginal references: chap. 4. 2, 17.