All the Chieftains Give Rods Including Aaron (Numbers 17:6).
‘And Moses spoke to the children of Israel, and all their princes gave him rods, for each prince one, according to their fathers' houses, even twelve rods, and the rod of Aaron was among their rods.'
So Moses did as Yahweh commanded and requested rods from each of the chieftains of the twelve tribes. These rods may well have been their symbols of authority. Thus twelve rods were gathered and Aaron's rod was placed among them.