"Adonai" is Hebrew for "my Lord", and was substituted by devout Jews for the name "Yahweh", out of reverence. With this second antiphon we progress from creation to the familiar story of God manifesting himself by name to Moses and giving his law to Israel as their way of life. We are also reminded of the Israelites' deliverance from bondage under pharaoh - a foreshadowing of our own redemption from sin. The image of God's arm outstretched in power to save his chosen people also brings to mind the later scene of Jesus with his arms outstretched for us on the cross.
Reflections on the O Antiphon: