The table below presents an aligned extract of verses or verselets in Ex27-20b, Ex29-40 Both verses/verselets discuss Temple processes requiring oil. The alignment justifies the Rashi comment that: The olive oil used for the Candellabrah was different than the oil used for annointing or for meal offerings. The verse calls the Minchah oil and annointing oil grounded olive oil. By contract the Candellabrah olive oil is called pure...grounded for lighting indicating a special process that prevented dregs from being in the oil so that the light would be pure. [In practice other olive oil processing involved weights and grinding to press out the oil while the processing of the Candellabrah olive oil involved letting the olives sit in a basket with the force of their weight causing the oil to naturally ooze. This natural process, therefore, resulted in no dregs, and consequently was highly suitable for light]

Verse	Text of Verse	Rashi comment
Ex27-20b	And you shall command the people of Israel, that they bring you pure olive oil beaten for lighting, for the lamp to burn always	The olive oil used for the Candellabrah was different than the oil used for annointing or for meal offerings. The verse calls the Minchah oil and annointing oil grounded olive oil. By contract the Candellabrah olive oil is called pure...grounded for lighting indicating a special process that prevented dregs from being in the oil so that the light would be pure. [In practice other olive oil processing involved weights and grinding to press out the oil while the processing of the Candellabrah olive oil involved letting the olives sit in a basket with the force of their weight causing the oil to naturally ooze. This natural process, therefore, resulted in no dregs, and consequently was highly suitable for light]
Ex29-40	And with the one lamb a tenth deal of flour mixed with the fourth part of a hin of ground oil; and the fourth part of a hin of wine for a drink offering.

Advanced Rashi: The Talmud, Menacoth, 86, presents controversy on how the oil was processed. I have therefore decided not to give details but rather to indicate purpose and function. The method for producing the Candellabrah olive oil had to be such that it was beaten for light and pure. This could happen if the olives were allowed to naturally ooze oil...as long as no weights or grinding was done there would be minimum dregs.

The Talmud (and Rashi) take the verse phrase ground for light to emphasize that The olive oil used in the Menorah had to be especially processed for light. Although there is controversy in the Talmud, the basic idea is agreed on: The processing of Candellabrah olive oil should be done without pressure from grinding since such pressure produces dregs which intefers with the quality of light. As already indicated one production approach is to let the olives lie in a basket until the weight of the olives causes the oil to seep out by itself (Without any pressure).