The Torah portion relates that Yitro heard about the good that God performed for the Israelites, as a result of which he came to the Israelite camp in the wilderness. The Sages disagree with regard to what caused him to leave his home and come.

“Yitro, priest of Midyan, father-in-law of Moses, heard all that God had done to Moses and to Israel His people, that the Lord took Israel out of Egypt” (Exodus 18:1). What report did he hear that caused him to come? He heard of the war with Amalek and came, as that is the topic written alongside it [i.e., immediately beforehand]; this is the statement of Rabbi Yehoshua. Rabbi Elazar HaModa’i says: Yitro heard of the giving of the Torah and came,(Mekhilta deRabbi Yishmael, Beshalah, Mesekhta deAmalek 1)