הלכה על במדבר 24:2

To remember what Amalek did to us: That we were commanded to remember what Amalek did to Israel - that he began to harass them when they left Egypt, before any other nation or kingdom raised their hand against them; and as the matter is stated, (Numbers 24:2) "Amalek is the first of nations." Its [Aramaic] translation (Onkelos Numbers 24:2) is "The first battle of Israel was Amalek" - because everyone was afraid of them when they heard of God's great hand that He used for them in Egypt. But the Amalekites, due to their evil hearts and evil disposition, did not turn their hearts to all of this, and harassed them [by waging war]. And as a result of this, Amalek was able to remove the great fear from the hearts of the other nations. And it is like the matter that our Rabbis, may their memory be blessed, analogized it (Pesikta Rabbati 12, Midrash Tanchuma on Devarim 25:17) to the analogy to a large boiling pot that no person could enter and [then] one [individual] comes and jumps and enters it. Even though he is burnt, he cools it for others. And about the memory of their matter is it stated (Deuteronomy 25:17), "Remember what Amalek did to you on your journey, after you left Egypt."