When God told Moses to take the staff that had struck the Nile, the Mekhilta explains the reason: it was because of Israel's "murmurings." The people had been complaining, and now God wanted Moses to perform a miracle with the very instrument they feared.
This was one of three occasions when Israel looked at sacred objects and saw only danger. The people murmured against three things — the incense, the Ark of the Covenant, and the staff — claiming each was nothing more than an instrument of punishment. They had watched these objects bring destruction, and they wanted nothing to do with them.
The incense had killed <strong>Aaron's</strong> sons Nadav and Avihu when they offered unauthorized fire. The Ark had struck down those who touched it improperly. The staff had unleashed ten plagues on Egypt and split the sea to drown Pharaoh's army. From Israel's perspective, these were weapons, not blessings.
God set out to change that perception. He deliberately used each of these "instruments of punishment" to perform acts of healing and salvation. The incense would stop a plague. The Ark would part the Jordan River. The staff would draw water from a rock to quench the people's thirst. The Mekhilta is teaching that sacred power is not inherently destructive or benevolent — it depends entirely on the context and the merit of those involved.