Yisro, Moshe’s father-in-law, heard about all that G-d had done for Moshe and his people Yisrael, when Hashem took Yisrael out of Mitzrayim.
Our minds almost instinctively take us to Rashi’s explanation that Yisro heard about the splitting of the Sea, and the battle with Amalek. We then try to figure out why these things in particular. Lots of ink spilled there!
But we are really asking the wrong question! What prompted the gemara[2] (from which Rashi took his comment) to offer any explanation at all? The pasuk states explicitly that he heard about all that Hashem had done! What is not to understand about “all?”
Here’s the thing. Yisro heard about the Exodus, but remained uncertain about the reason for it and its extraordinary drama. Perhaps Hashem performed it because of the enormous evil of the Egyptians, for perpetrating the terrible injustice of the enslavement and persecution of an innocent population. (And maybe a few other not nice things they were into.) Not so much to do with the Bnei Yisrael. They were just less evil. Alternatively, perhaps His primary focus was His people, whom He wished to support and deliver. Everything to do with us
This question was of practical interest to Yisro; it was not just academic speculation. If Hashem’s agenda was benefiting the Jews, then he reasoned that Hashem would accept converts to the same cause. Hashem would surely welcome those who were prepared to make common cause with the Bnei Yisrael, and he, Yisro, would be the first in line.
If, on the other hand, Hashem’s actions were primarily about punishing the Egyptians and asserting His own dominance, then the fact that the Bnei Yisrael were the beneficiaries of His actions was largely irrelevant. It would say nothing at all about the propriety of joining up with Moshe’s people.
Yisro, in fact, heard everything about the incredible events surrounding the Exodus. But he was not sure which of the two explanations was true. At least until he heard about the splitting of the Sea, and beating back the Amalekite attack. If this were just about Egyptian sinfulness, why would Hashem have so miraculously supported the Jewish people after their release from bondage? The Egyptians had suffered a crushing defeat during the makos, and had been forced to free their slaves. His point as Master of the Universe and hater of evil had been made.
Standing by the Bnei Yisrael could only mean that He was declaring His love for them as His people. When Yisro heard about the splitting of the Reed Sea, and about Amalek’s attack, he knew that this was the case. And that he could join them as well.
Yisro was not the first to get the memo. The Egyptians themselves came to the same conclusion at krias Yam Suf. As their chariots froze in place in the mud of the seabed, they exclaimed, “Let us flee from the Bnei Yisrael! Hashem is fighting for them against Egypt.” For them – and not just against us and our sins.
Yisro correctly read Hashem’s intentions to take a people as His own, and nurture them for all times.