Rashi on Leviticus 24:4/רש"י על ויקרא כ״ד:ד׳

1המנרה הטהרה THE PURE CANDELABRUM — It was so called because it was made of pure gold. Another explanation is: he shall set the lights in order upon the purity of the candlestick, implying that he must first purify (cleanse) it and remove its ashes beforehand (the words therefore mean: on a clean candlestick; cf., however, Sifra, Emor, Section 13 12 where the word is explained differently).