Deutéronome 25:18

...An additional possibility: This is the language of cool and heat, cooled you and stopped you from boiling. All the nations of the world were afraid to fight you [Israel] and this one came and started and showed the way to others. It is likened to a legend of a boiling bath that no creature could enter. A scoundrel came and jumped in. Even though he was scalded, he cooled it down for others.

how they overtook you in the way, and slew every one of those among you who were thinking to go aside from My Word; the men of the tribe of the house of Dan, in whose hands were idols (or things of strange worship), and the clouds overcast them, and they of the house of Amalek took them and mutilated them, and they were cast up: but you, O house of Israel, were faint and weary from great servitude of the Mizraee, and the terrors of the waves of the sea through the midst of which you had passed. Nor were the house of Amalek afraid before the Lord.

happened upon you as in “all that had befallen them” [Genesis 42: 29].

sheared off your rear [Hebrew: vayzannev bekha] i.e., cut off your tail [Hebrew: zanav] — namely, those who were enfeebled, The word enfeebled [Hebrew: neḥeshalim] is probably the same as the word neḥelashim. The two consonants transpose, as in “sheep” [Hebrew: keves̀] [Leviticus 4: 32] and “lamb” [Hebrew: kes̀ev] [Leviticus 3: 7].

you were weak They had just arrived at Refidim [Exodus 17: 8], where the people thirsted after water (for so it is written [Exodus 17: 3]).

and lagging, because they had no strength to walk.

The phrase feared not refers to Amaleq. The verb is in the perfect tense, as in “it was too difficult for you” [Exodus 18: 18], “when Isaac was old” [Genesis 27: 1], and “as he used to enjoy” [Genesis 27: 9].

אשר קרך בדרך, meaning “accidentally,” unforeseen. The construction קרך from the root קרה is parallel to the construction עשך from the root עשה, Deut. 32,6 הוא עשך ויכוננך, “He has shaped you and made you durable.”

ויזנב בך כל הנחשלים, “and he (Amalek) cut down the stragglers in your rear.” They would cut of the organ that had been circumcised and threw it into the air shouting: “this is what you chose, take it!” According to our author this is what the psalmist refers to in Psalms 79,12 when he said: והשב לשכנינו שבעתים אל חיקם, pay our neighbours back sevenfold for the abuse they have flung at You o Lord. Another interpretation of that verse understands it as the Amalekites having ridiculed the Torah as per Psalms 12,7: מזקק שבעתים, “which is refined sevenfold.” [How could Amalek have ridiculed the Torah which had not been revealed yet to the Jewish people at that time? Ed.]

ולא ירא אלוקים, “and he did not fear G–d,” by cheating with weights. [According to this interpretation the subject in this verse is not Amalek but Israel.] The Torah had used the expression ויראת אלוקיך, “you shall fear the Lord your G–d,” when warning us not to cheat with weights and measurements] If the Israelites had heeded this warning, Amalek would not have been allowed to harm them when attacking them. Our author quotes Proverbs 11,1: מאזני מרמה תועבת ה' ואבן שלמה רצונו, “dishonest scales are an abomination to the Lord; an honest weight pleases Him,” as support for his interpretation. Solomon continues in the verse following in Proverbs, by saying: בא זדון ויבא קלון, “evil is followed by disgrace in its wake;” and the Torah, immediately before inserting the paragraph of Amalek’s attack, had written that all the people guilty of the sins listed in the previous paragraph had committed an abomination against the Lord. (Compare Tanchuma, section 8 on our portion)