Vayikra 24:2

צו את בני ישראל COMMAND THE CHILDREN OF ISRAEL [THAT THEY BRING UNTO THEE CLEAR OLIVE OIL, BEATEN, FOR THE LIGHT] — This is the section containing the commandment concerning the lamps, whilst the section beginning with ואתה תצוה (Exodus 27:20 ff.) which also deals with the lamp is only mentioned there for the sake of giving an orderly account of the work of the Tabernacle, to explain what the purpose of the candlestick was — for thus do those words ואתה תצוה imply: “and thou wilt at some future time command the Children of Israel” about this. שמן זית זך CLEAR OLIVE OIL — Three different qualities of oil come forth (are extracted) from the olive tree, the first of which is called זך, “clear”. They are all fully explained in Treatise Menachot 86a and in Torath Cohanim (Sifra, Emor, Section 13 1-3). תמיד (continually not continuously) here implies from night to night. It has the same meaning as in עולת תמיד a “continual” burnt offering which was only sacrificed from day to day (cf. Rashi on Exodus 27:20).

צַ֞ו אֶת־בְּנֵ֣י יִשְׂרָאֵ֗ל וְיִקְח֨וּ אֵלֶ֜יךָ שֶׁ֣מֶן זַ֥יִת זָ֛ךְ כָּתִ֖ית לַמָּא֑וֹר לְהַעֲלֹ֥ת נֵ֖ר תָּמִֽיד׃

Command the children of Yisra᾽el, that they bring to thee pure oil olive beaten for the light, to cause the lamps to burn continually.