Rabbi Yossi ben Zimra noticed a single word in the Torah that most readers skip right past — and from it, he derived an astonishing claim about the staff of Moses. When God instructed Moses to bring water from the rock at Horeb, He said: "you shall strike into the rock" (Exodus 17:6). Not "on the rock." Into it.
The preposition changes everything. If the staff were ordinary wood, it could strike the surface of a rock. But the Torah says Moses struck into the rock — the staff penetrated solid stone. Rabbi Yossi ben Zimra concluded that Moses' staff must have been made of sapphire, one of the hardest substances known in the ancient world. Only a rod of sapphire could drive into rock rather than merely hitting its surface.
This tradition transforms the staff from a shepherd's tool into a supernatural instrument. The same staff that turned into a serpent before Pharaoh, that split the Red Sea, that struck the Nile and turned it to blood — that staff was not wood at all. It was crystallized divine power, hard as gemstone, capable of piercing the earth itself.
The Mekhilta's attention to prepositions is characteristic of rabbinic reading. Every word in the Torah is precise, and the difference between "on" and "into" cannot be accidental. If God said "into," then the staff went into the rock. And if the staff went into the rock, it must have been harder than rock. The sapphire staff of Moses becomes, in this reading, one of the most remarkable objects in all of Jewish tradition — a weapon forged from heaven's own material, placed in the hand of a prophet.