Notes on the Bible, by Albert Barnes, [1834], at sacred-texts.com
Ezekiel Chapter 31
In the third month - More than a month before Jerusalem was taken (compare Jer 39:2).
Fifth prophecy against Egypt: a warning to Pharaoh from the fate of the Assyrians. The Assyrian empire, after having been supreme in Asia for four centuries, had been overthrown by the united forces of the Babylonians and Medes, in the year of the battle of Carchemish (605 b.c.), which had broken the power of Egypt. This gives force to the warning to Egypt from Assyria's fall.
His plants - Rather, her plantation. The water represents the riches and might which flowed into Assyria.
When be shot forth - Or, when the deep water sent forth its streams.
Garden of God - Paradise.
Assyria's fall.
More accurately: Therefore I will deliver him, etc ... he shall surely deal with him. I have driven him out, etc.
Their trees - Rather, as in the margin, "standing unto themselves" meaning "standing in their own strength." The clause will then run thus: "Neither all that drink water stand up" in their own strength. "All that drink water" means mighty princes to whom wealth and prosperity flow in. The Egyptians owed everything to the waters of the Nile. The substance is, that Assyria's fall was decreed in order that the mighty ones of the earth might learn not to exalt themselves in pride or to rely on themselves, seeing that they must share the common lot of mortality.
Effect of Assyria's fall.
I covered the deep - To cover with sack-cloth was an expression of mourning Eze 27:31. The deep, the source of Assyria's prosperity Eze 31:4, was made to mourn, being dried up instead of giving forth its waters, its glad abundance.
For him - Upon his account.
Floods ... great waters - Or, rivers ... the multitude of waters (as in Eze 31:4-5).
Lebanon represents the country which Assyria governed; "the trees," the tributary princes.
See the marginal references.
His arm ... - The subject princes who were his strength and support in war.
Application to Pharaoh.
The uncircumcised - The Egyptians, at least their nobles, were circumcised. Pharaoh should thus be dishonored with those whom the Egyptians themselves deemed unclean.