What did Aaron's staff produce overnight in the Tent of the Testimony?

Answer: Almonds

Aaron's staff, representing Levi, sprouted, budded, blossomed and produced almonds by the next day.

“The next day Moses entered the Tent of the Testimony and saw that Aaron’s staff, representing the house of Levi, had sprouted, put forth buds, blossomed, and produced almonds.”— Numbers 17:8 (BSB)