Exodus 27:20 states: "And you are to command the Israelites to bring you pure oil of pressed olives for the light, to keep the lamps burning continually." The Mishnah (Menachot 8:4) teaches that there were three harvests of olives, and each crop gave three kinds of oil (for a total of nine types of oil). The first crop of olives was picked from the top of the tree; the olives were pounded and put into a basket (Rabbi Judah said around the inside of the basket) to yield the first oil. The olives were then pressed beneath a beam (Rabbi Judah said with stones) to yield the second oil. The olives were then ground and pressed again to yield the third oil. Only the first oil was fit for the menorah, while the second and third were for meal-offerings. The Beit Shemesh Municipality is not only pruning olive trees in Ayalon Park, but have employed contractors who harvest the first oil of the first crop for educational purposes.