R. Acha b. R. Oshiyah says: The speaking was on Rosh Chodesh, the taking on the tenth, and the slaughtering on the fourteenth. You say this, but perhaps the speaking and the taking were on the tenth, and the slaughtering on the fourteenth? It is, therefore, written "Speak to the whole congregation of Israel, saying." Let "saying" not be written. Why is it written? To separate (between the speaking and the taking). You must posit the first formulation, then, and not the second.