Numbers 17:1

And the LORD spake unto Moses, saying,

The Lord spoke to Moses directing that a rod be collected from each tribe inscribed with its ancestral name, with Aaron's name written on the rod for Levi. Those rods were to be placed before the testimony as a test to settle Israel's challenge to Aaron's priesthood, the rod that blossomed identifying the tribe God had chosen. Aaron's rod for Levi alone budded, blossomed, and bore almonds overnight, proving God had chosen Aaron and confirming the priesthood in his family, which silenced the people's complaints and established its authority.

The rod was preserved as a lasting witness to later generations and warning against rebellion and renewed murmuring. The sign led the Israelites to recognize their wrongful accusations and rebellion, to confess their sin, and to acknowledge the punishment of the rebels as just.