Blot out the memory of Amalek or kill his descendants?

Question

Can a prophet issue commands that go beyond the Torah?

The Torah says only to blot out Amalek's memory:

The Lord said to Moses, "... I will utterly blot out the memory of Amalek from under heaven." [Ex. 17:14, Deut. 25:19]

But later Samuel tells King Saul to wipe out the Amalekites physically:

And Samuel said to Saul ... “Thus said the Lord of Hosts: ... Go and attack Amalek, and utterly destroy all that they have, and do not spare them. Slay man and woman, infant and suckling, ox and sheep, camel and ass.” [1Sam 15:1-33]

Isn't that going beyond the Torah? Some commentators have said as much:

-Rabbi Samson Raphael Hirsch: the command was to destroy “the remembrance of Amalek”, not kill Amalekites. [Hirsch on Deut. 25]

-The Sfat Emet: the command was to hate Amalek, not perform any action. [Shemot Zachor 346]

-The Chafetz Chayyim: God will eliminate Amalek. Jews are only commanded to remember what Amalek did to them.

-Rabbi Simcha Bunim: the Torah says “blot out the memory of Amalek” (כִּֽי־מָחֹ֤ה אֶמְחֶה֙ אֶת־זֵ֣כֶר עֲמָלֵ֔ק מִתַּ֖חַת הַשָּׁמָֽיִם׃) in the singular, not the plural. Not the Amalekites, but Amalek.

I know the Talmud says we must not try to kill Amalekites today because we lost the ability to recognize them:

But Sennacherib, King of Assyria, had come up already and confused all the lands as it is said in Isaiah, “I have removed the bounds of the peoples,” [Isaiah 10:13] So the rabbis decreed that the seven nations of Canaan no longer exist because the Assyrians [and not the Israelites] wiped them out. [Yoma 54a]

On this basis, 19th-century Turkish rabbi Hayyim Palaggi said that we lost the tradition of how to recognize Amalekites, so we cannot fulfill the commandment to wipe them out. [Enei Kol Hai 73, on Sanhedrin 96b]

But my question stands: How can a prophet issue commands that go beyond the Torah? Deut. 13:1 says: Do not add to or subtract from the Torah.

Answer 1

The prophet on his own cannot add or subtract from the torah. However, Hashem can tell the prophet to do a specific action for a problem that occurs at a specific time (הוראת שעה). Thus Shmuel was giving Shaul instructions that Hashem had said to pass on and do. This was the method that Hashem had said to use in order to destroy the memory of Amalek.

Another example of Hashem issuing specific commands that would otherwise be forbidden would be His telling Eliyahu Hanavi to bring a sacrifice and challenge the priests of baal. Since this was after the building of the temple in Yerushalayim, it was normally forbidden to bring a sacrifice on a private altar. Had Eliyahu attempted to do it himself it would have been forbidden.