From the Museum of the Prado, a powerful Annunciation by El Greco, this one combining the Annunciation with Mary's title (and icon) in the Eastern Church, "Our Lady of the Burning Bush." An antiphon in the Evening Prayer for the Solemnity of Mary, the Mother of God (January 1) also sees the Burning Bush as a "type" or prophetic foreshadowing of Mary: "Your blessed and fruitful virginity is like the bush, flaming yet unburned, which Moses saw on Sinai. Pray for us, Mother of God."
The Museum website offers extensive commentary on this work.