This chapter continues the effort to dissuade the people of Yehuda from forming an alliance with Egypt, focusing on a sin we’ve encountered throughout the book: the sin of pride. The people of Yehuda fail to properly grasp the relationship between humanity and God. They are overly impressed by Egypt’s great military strength, but Yeshayahu calls on them to stop being impressed by human power and instead place their trust in God: "Placing Their Trust in Chariots – So Many – and horsemen – how powerful they are – and do not turn to Israel's Holy One, do not seek after the Lord." (Yeshayahu 31:1)

God will save the people of Israel from the Assyrian threat in a miraculous way, and their enemies will perish by "a sword not of man” (Yeshayahu 31:8). This deliverance will lead the people of Yehuda to properly understand the true balance of power. They will recognize God’s greatness compared to human beings and will no longer worship the works of their own hands. We can notice the thematic closure with the beginning of the book, highlighting their repentance from idolatry—a sin rooted in pride: "For on that day each man will recoil from his silver gods, his golden gods, which your hands made for you, sinning" (Yeshayahu 31:7), Compared to the earlier description of sin in Chapter 2: "their land is filled with false gods; they bow to the work of their hands; their own fingers formed them" (Yeshayahu 2:8).

Prof. Amos Frisch (see excerpt here) examines references within the books of Nevi’im to the prohibitions imposed on the king (as part of Parashat Hamelekh, in Devarim 17). These include the prohibitions of amassing horses, wives, silver and gold, as well as the prohibitions of bringing the people back to Egypt and deviation from loyalty to God (“let his heart be led astray”). Various passages in Sefer Shoftim contain allusions to Parashat Hamelekh, creatively applying its principles to new historical realities.
The article discusses seven such passages, and in the excerpt here only the brief discussion of Yeshayahu’s prophecies about Egypt in Chapters 30 and 31 is presented. See the table he brings and the two columns of chapter 30 and 31, where the basis of the references to Parashat Hamelekh are illustrated. Pay attention as well to the concluding remarks regarding the considerations made to determine the application of the law.

Source of the article: "הדים בספרי נביאים לאיסורי 'חוק המלך' שבתורה"