“You shall command the children of Israel and have them bring to you clear olive oil, [made from olives that were] crushed for lighting, to keep the lamp burning continuously.” (Exodus 27:20)
According to the Oral Torah, only the best, first drop of oil that was pressed from each olive could be used for lighting the Menorah (Menachos 86a). The remainder of the oil in each olive, however, could be used for the meal offerings, since they didn’t require the same degree of purity.
Why the disparity?
Some explain that the light of the Menorah represents Torah (Proverbs 6:23), while the meal offerings symbolize physical sustenance, livelihood and material needs.
When it comes to Torah and our spiritual pursuits, we need to press ourselves and seek the highest level possible. However, when it comes to our materialistic activities, things can be good enough and we don’t need to exert ourselves to the max.