Vayedaber Hashem el Moshe lei'mor is the most commonly occurring verse of the Bible. While it is usually translated as, “G-d spoke to Moshe, saying”, our rabbis saw additional meaning in the word lei'mor. If it only meant “saying”, then it would be superfluous; if the Torah tells us that G-d spoke to Moshe, then surely something was said.
The Torah was edited with great precision. This is the idea behind the notion that "there is no chronological order to the Torah". Items are placed were they can teach the greatest messages—form can be as important as substance.
"And Yitro, the priest of Midian, the father-in-law of Moshe, heard all that G-d did for Moshe and to Israel his people, that G-d had taken the Israel out of Egypt" (Shemot 18:1). Of course, Yitro was not the only one who heard all that G-d had done. Yet he was the only one who was listening; the only one who cared enough and was moved enough to actually do something. While others likely were impressed to hear that a slave nation took on the worlds superpower, such lasted the 30 seconds or so they spoke about it. They then moved on with their daily activities.