Amalek's attack on Israel at Rephidim is only a few verses in (Exodus 17). The Targum Jonathan expands it into an epic confrontation with backstory, supernatural geography, and a war whose consequences span three ages of the world.
The Hebrew Bible says Israel camped at Rephidim and there was no water. The Targum explains why: Rephidim was "a place where their hands were idle in the commandments of the law, and the fountains were dry." The name itself becomes a moral diagnosis. The water dried up because Israel stopped observing the Torah. Thirst was a symptom of spiritual neglect.
Then Amalek arrived. The Targum says he "came from the land of the south and leaped on that night a thousand and six hundred miles." This is not a normal military march. Amalek supernaturally vaulted across the desert to reach Israel, driven by the ancient grudge "between Esau and Jacob." He specifically targeted the tribe of Dan, "for the cloud did not embrace them, because of the strange worship that was among them." The protective clouds of glory had gaps, and Amalek exploited them.
Moses told Joshua to choose men "strong in the precepts, and victorious in fight." Military skill alone was insufficient. The Targum makes Torah observance a prerequisite for combat. Moses then ascended the hill "prepared with fasting, with the righteous fathers of the chiefs of the people, and the righteous mothers who are like the hills." He invoked the merit of the patriarchs and matriarchs as spiritual weapons.
When Moses raised his hands, Israel prevailed. When he lowered them, Amalek prevailed. The Targum specifies these were hands "in prayer," not just lifted arms. And God's oath to destroy Amalek extends across "three generations: from the generation of this world, from the generation of the Messiah, and from the generation of the world to come." The war with Amalek will not end until history itself ends.