8 And they shall know that I am Yahweh, when I have set a fire in Egypt, and when all her helpers shall be destroyed.
Nothing can protect a provoking people when Yahweh comes forth to contend with them. Not only shall they fall, but those also that trust in them. The great power of the south is now addressed by the prophet, as he speaks of the devastation to be faced by Egypt and her helpers. Egypt was the oppressing power out of which Yahweh drew His national Son; it remained to constantly afflict Israel, and for which it was now to come under the judgmental rod of God. •
So the prophecy portrays:  Egypt's power overthrown: vv. 1-19.  The decisive defeat of Pharaoh: vv. 20-26. The dating of the prophecies presented by Ezekiel shows that each was brought forth by the political events of the time, and should be studied in connection with them. Pharaoh Necho was defeated by Nebuchadnezzar at Carchemish (BC604; Jer. 46), and was succeeded by his son Psammetik 11 in BC594. He invaded Ethiopia and died in BC588, leaving the throne to his son Uah-prahet, Pharaoh-hophra of Jer. 44:30.
Herodotus states that this Pharaoh attacked Tyre and Sidon, failed in an enterprise against Cyrene, and was deposed by Amasis in BC569. Zedekiah courted Egypt (Eze. 17:11-18), vainly hoping for help. Because the associate nations with Egypt mocked at Israel's troubles (Eze. 30:3), now their time of judgment had come. •
This is the divine principles, by which Yahweh allows His people to suffer, whilst ultimately delivering them from those who gloat over their distress. The prophet figuratively walks through the land of the south, observing its former glory in the rivers (v. 12), the great cities of the Nile, and describes the dissolution of Egypt's power against the picture of its former glory.
Note the constant reminder of the divine Power, through the "Word of Yahweh," and by which all will "know that I am Yahweh" (vv. 8, 19, 25, 26). - GEM, Logos.