Yisro’s grand realization
וישמע יתרו כהן מדין חתן משה את כל אשר עשה אלקים למשה ולישראל עמו כי הוציא יקוק את ישראל ממצרים
Yisro, the priest of Midian, the father in-law of Moshe, heard all that G-d did for Moshe and for His nation of Yisroel, since Hashem took Yisroel out of Egypt
As the Jews traveled towards Mount Sinai for the giving of the Torah, Moshe’s father in-law Yisro made a grand appearance. The Torah tells us that he heard what had happened to the Jews, and decided to join them and convert to their religion. The verse doesn’t specify what Yisro heard which inspired him to convert, but the Midrash elaborates. One opinion says that Yisro heard about the splitting of the sea. In fact, the entire world heard about this amazing miracle. According to this opinion, only Yisro took the miracle as a call to action to join the Jewish people. Another opinion says that Yisro heard about the war with Amalek. Right after the Exodus, the Jews were ambushed by this nation which represents pure evil. It was this war that inspired Yisro to convert to the Jewish religion.
The latter opinion at first glance is quite surprising. It’s saying that Yisro hearing about the splitting of the sea wasn’t inspiring enough. It was the one of the single greatest revelations of Hashem in history. The entire world was blown away by the awesomeness of the miracle. Although no one took the next step to convert, it’s surprising that something as relatively insignificant as the war with Amalek could be the impetus. The war wasn’t even all that impressive. There were causalities on both sides, without any clear victor. How are we to understand this?
One explanation is based on understanding the true catalyst to the war with Amalek. Hashem caused the war to happen in order to strengthen the foundations of the Jewish people’s faith. They were suspicious that perhaps all the miracles they had experienced in Egypt were all Moshe’s doing. Perhaps he was just a really powerful sorcerer. Or maybe his staff had magical properties. To remove all these mistaken ideas, Hashem engineered the nation of Amalek to attack. This wouldn’t be a normal battle, with the nation’s leader at the forefront. He was to literally sit this battle out, as Moshe sat on a high mountain, with the staff in his hand. The people quickly realized that their success in the battle was solely a result of their allegiance to Hashem. Moshe wasn’t involved at all. With that, they had no doubt that Hashem was entirely behind their salvation from Egypt.
Now, if the Jewish people, who had witnessed first-hand the miracles of Egypt, could have such distorted views of things, how much more so would it make sense to say the rest of the world got things wrong. The nations thought that the splitting of the sea was just some incredible act of sorcery on Moshe’s part. This would explain why no one was inspired to convert to Judaism. They assumed it wasn’t a revelation of Hashem’s guiding hand in human history.
However, Yisro didn’t stop listening. Soon after the splitting of the sea, the war with Amalek happened. Yisro heard about both events. He understood the message that Hashem was sending the Jewish people: Moshe isn’t behind everything. Hashem showed the people that their success was solely dependent on their faith and service of Hashem. They realized that G-d was behind their miraculous salvation from Egypt, and Yisro got the same message. It was this latter realization, combined with the awesome miracle of the splitting of the sea, which inspired Yisro to join the Jewish people.
Another explanation for what inspired Yisro is based on the ramifications of the war with Amalek. It also explains the whole grand entrance Yisro made. He sent messengers to Moshe to inform him of his arrival, informing him that he would be joining the Jewish people. Why did Yisro made this grandiose announcement? Further, when news spread that Yisro had arrived to convert, an entire entourage was formed to escort him to the Jewish camp. There was tremendous fervor, as everyone wanted to be a part of the parade. Why was there such a big deal? We know that Yisro wasn’t the first prominent person to want to join the Jewish people. What made him so special?
Yisro had specific intent with his grand entrance. When Chazal tell us that he heard about the war with Amalek, it wasn’t regarding the victory of the Jews. As already stated, it wasn’t such a victorious battle. Rather, he heard about the audacity of the Amalek people. Nations throughout the world were still in shock and awe at the great miracle of the splitting of the sea. No one dared face the Jews at that point. Brazenly, the Amalek people decided to break the ice. They provided room for others to take on the Jews in the future. This war could have had terrible ramifications for the Jews.
Yisro knew Amalek’s intention, and wanted to show the nations of the world just how special the Jewish people were. Yisro was a prominent person in the land of Midian, a high priest who had association with every known religion. He dropped it all in order to convert to Judaism and join this people. It was done with pomp and ceremony, to send a message: don’t mess with the Jews. Moshe intuited this was Yisro’s intention, and sent a huge band of followers to escort him to their camp. Yisro’s positive intentions caused him this huge honor, as well as the honor of having the parsha named after him.
 Based on Be’er Yosef to Exodus 18:1
 Exodus loc. cit.
 It’s actually a dispute when Yisro came: before or after the giving of the Torah (see Rashi to Exodus 18:13 and Zevachim 116a). The chronological reading of the verses was chosen
 Mechilta Masechta D’Amalek § 1and Zevachim loc. cit.
 Rashi to our verse combines both opinions into one. The Midrash (loc. cit.) brings a third opinion, that he heard about the giving of the Torah (following the opinion that Yisro didn’t come earlier)
 See Psalms 106:22 and Avos 5:4
 Exodus 15:14
 See Deuteronomy 25:18. Also, a true victory would have annihilated Amalek completely
 This is also a question on Rashi’s commentary, which implies that Yisro only converted because he heard both events. Again, the splitting of the sea wasn’t enough
 Exodus 17:9
 See Rashi to Numbers 21:8, quoting Rosh Hashanah 3:8
 See Midrash Tanchuma Balak § 3, brought by Rashi to Numbers 22:4 and Esther Rabbah 7:13
 The Zohar (parshas Ki Sisa) explains that the Erev Rav who joined the Jewish people (Exodus 12:38) included the dignitaries from Egypt
 Midrash Tanchuma Ki Seitzei § 9, brought by Rashi to Deuteronomy 25:18
 Exodus 3:1
 See Rashi to Exodus 18:11
 See Zohar II parshas Yisro