The Torah records that the reason Hashem didn’t take Bnei Yisrael via Derech Eretz Plishtim is because of war. But Hashem specifically told Moshe that they had to stop at Har Sinai first to serve God (תעבדון את האלוקים על ההר הזה). Hashem prevents war by taking Bnei Yisrael on a circuitous route and by having the Egyptians drown in the Yam Suf, yet they end up having to fight Amalek!
Why are they armed (חמושים)?
Delivered at the OU Israel Center, January 17th, 2019 (11 Shevat 5779)