Rashi on Leviticus 6:6/רש"י על ויקרא ו׳:ו׳

1אש תמיד — The redundant word תמיד (because it could have written לא תכבה המזבח ‎אש תוקד על‎ ; for this, too, would imply that it must be continually burning since it states that it must never go out) intimates: The fire about the use of which the expression תמיד is used, viz., that by which the lamps of the Candelabrum were kindled, with reference to which it is said, (Exodus 27:20) “to light the lamps continually (תמיד), this, too) should be ignited from the fire on the outer altar Yoma 45b).

2‎‎תכבה‏ ‎לא‎ IT SHALL NEVER GO OUT — One who extinguishes the fire on the altar transgresses two negative commands (this and that contained in v. 5).