Exodus 27:20

And thou shalt command the children of Israel that they bring thee pure oil olive beaten for the light to cause the lamp to burn always. The oil used in the Tabernacle was not that pressed out of olives by stamping with the feet or by means of an oil-press, but that which flowed from the ripe olives after they were cut or bruised. This oil was pure and clear, and therefore served well for burning in the Holy Place.