A jar of Manna was placed in the Holy of Holies as a memorial and testimony to the Almighty's Divine protection over the Children of Israel. During the forty year period that Israel was in the desert, the Manna descended from the sky for them each day, with the exception of the Sabbath. (Source: Exodus 16, 11-36) 
Aaron's Staff
Contents:   Part I,    Part II,    Part III,    Part IV,    Part V,    Part VI,    Part VII