Leviticus 6:12-13

Young's Literal Translation

¹² `And the fire on the altar is burning on it, it is not quenched, and the priest hath burned on it wood morning by morning, and hath arranged on it the burnt-offering, and hath made perfume on it [with] the fat of the peace-offerings;

¹³ fire is continually burning on the altar, it is not quenched.