In Parshat Emor (Vayikra 24:1-2) we read about the olive oil that was needed for the menorah:
God said to Moshe, saying; “Command B’nai Yisrael that they bring to you pure olive oil, pressed for lighting (shemen zayit zach katit lamaor) to keep the lamp burning constantly.”
This verse sounds similar to the opening words of Parshat Tetzaveh (Shmot 27:20):
“You shall command B’nai Yisrael that they bring to you pure olive oil pressed for lighting (shemen zayit zach katit lamaor) to keep the lamp burning constantly.”
Ramban proves why both statements are needed:
In Shmot, B’nai Yisrael brought the olive oil as a donation along with all of the other donations that were brought for the Mishkan (Tabernacle). In Vayikra, the oil which the princes brought as a donation was used up and therefore God commanded B’nai Yisrael to take from the public treasury throughout the generations pure olive oil, pressed for lighting as was the first oil (of the princes).
The Mishna in Menachot 86a explains that the oil used for the lighting of the ner tamid (menorah) must be from the first drops of oil that drip from the ripest of olives that are pounded.
The oil that emerges when the olives are pressed further with beams or with stones is a lower grade oil which is used for the menachot offerings but is not pure enough for the menorah.
Shmot 29:40 refers to the mincha offering which was brought with the daily tamid sacrifice:
“And a tenth of an ephah (measure) of fine flour mixed with one fourth of a hin of pressed olive oil (bashemen katit)…”
The Talmud, Menachot 86b explains that the oil of crushed olives (the purest oil) may be used for the menachot offerings but is not required in order to spare the Jews the expense of obtaining it.
Many mincha offerings are brought every day and if we needed to only use the purest oil from crushed olives, then the demand would drive up the cost. The menorah only requires one “log” of oil for each of the seven lamps (3 ½ “lugin” a day). This is a relatively small amount of oil that can be obtained at a minimal cost.
The Gemara asks why we care about sparing Jews the extra expense.
Rabbi Elazar said: The Torah is concerned with Israel’s wealth.
The Torah does not want us to incur even minor financial losses. If we are able to continue pressing the olives further with a beam or with a stone to draw out more oil, why should we waste what is left of those olives? It is perfectly acceptable for that oil to be used for the menachot offerings.
The same is true with the foods and products that we have in our homes. Instead of wasting food, we should make it a priority to eat whatever we bought before it gets spoiled. As well, we should try to repurpose as many products as we can. It will save us money in the long run as well as save the environment.