Beaten out of the olives with a pestle, which is freer from dregs than that which is squeezed out with a press. To burn always, i.e. at all the times. appointed; daily, though not continually; as the lamb offered only every morning and every evening is called a continual burnt-offering, Exodus 29:42. For that these were lighted only at the evening, may seem probable from the next verse, and from Exodus 27:21, Exodus 30:8 Leviticus 24:3 1 Samuel 3:3 2 Chronicles 13:11. But because Josephus and Philo, who were eye-witnesses of the temple service, and had no temptation to lie in this matter, expressly affirm, that some lights did burn in the day-time; and it may seem indecent and improbable that God should dwell and the priests minister in darkness, and there were no windows to give light to the tabernacle by day; it may be granted that some few burnt in the day, and all in the night, and that the latter is only mentioned in the places alleged, as being a more solemn time when all are lighted.
Related Commentaries of Exodus 27:20
Exodus 27:20
20 And thou shalt command the children of Israel, that they bring thee pure oil olive beaten for the light, to cause the lamp to burnb always.