(14) Then the Lord said to Moses, “Inscribe this in a document as a reminder, and read it aloud to Joshua: I will utterly blot out the memory of Amalek from under heaven!”
(15) And Moses built an altar and named it Adonai-nissi.
(16) He said, “It means, ‘Hand upon the throne of the Lord!’ The Lord will be at war with Amalek throughout the ages.”
(14) Then the Lord said to Moses, “Inscribe this in a document as a reminder”: This is the first time in the Torah that we encounter an instruction to preserve memory by committing it to writing, instead of simple oral transmission. It is a document whose purpose is to preserve memory. Because the war with Amalek will last for many generations, a written record of it is needed to serve as a guide for the future.
And read it aloud to Joshua: Because Joshua is now commander in chief, it is essential for him to understand the meaning of this directive. The Midrash sees in this an allusion to the succession of leadership in the Jewish nation, which after Moses’ death, will pass to Joshua.
I will utterly blot out the memory of Amalek from under heaven! Joshua has only weakened Amalek. But God now confirms that this was just the beginning of the task, to be completed in due time, that will ultimately end with a total annihilation of Amalek.
I will utterly blot out: Later, in Deuteronomy, erasing the memory of Amalek is expressed as a solemn commandment that is binding on the entire Jewish nation. “When the Lord your God grants you safety from all your enemies around you … you shall blot out the memory of Amalek from under heaven. Do not forget!” (Deut. 25:19)
Here, however, God says, “I will utterly blot out the memory of Amalek from under heaven!” For now, God Himself assumes responsibility for this task.
I will utterly blot out the memory of Amalek: This is not about blotting out all memory of Amalek in the conventional sense. On the contrary, by being recorded in the Torah, this memory will remain forever. Rather, the “memory of Amalek” refers to the people who are living reminders of Amalek – his heirs, and the successors to his work. Those people must be destroyed.
From under heaven: In this world as we know it, the world that is “under heaven,” there is be no place for Amalek, the quintessential bearer of evil. But above heaven, in higher worlds, there is a place for everything, because there even evil plays a positive creative role.
(15) And Moses built an altar: As a means of reinforcing in the minds of the people a correct understanding of the events that have just taken place, Moses builds an altar of gratitude. Amalek “came” (17:8) because the Jews did not feel a connection with God. To correct this failing, Moses builds an altar and proclaims, “The Lord is my banner,” in order to give the people a stronger sense of God’s eternal presence, which is the basis for victory over Amalek. Whenever the Jewish nation falls short in their awareness of God’s presence among them, Amalek attacks.
And named it Adonai-nissi: “The Lord is my banner.” Only by turning to Heaven can the Jewish people be victorious. Moses’ hands are symbolic of this. His hands, raised to heaven in the heat of the battle, served as a banner for the Jewish people.
(16) He said, It means, ‘Hand upon the throne of the Lord!’: This wording is a typical formulation of an oath.
The Lord will be at war with Amalek throughout the ages: The nature of this war will be further revealed in Deuteronomy (25:17 ff.), where we will examine it in greater detail.