After the first Passover and their deliverance from slavery in Egypt, Moses and the Israelites entered into a Covenant with God. Among the signs of this Covenant were two stone tablets upon which the Ten Commandments (or Decalogue) were inscribed. God instructed the Israelites to make a precious Ark of gold to house these laws {see Exodus 25:10-22 and 37:1-9}. He had earlier asked them to keep some of the manna from the desert for future generations to see {16:33}, and this would also be placed inside of the sacred vessel with the tablets {see Hebrews 9:4}.
Through the Last Supper and Calvary, the Old Law was superseded by Jesus Christ and His New Law. As the Mother of Jesus, the Virgin Mary was, in the words of St. Athanasius {died: 373 A.D.; feast: May 2}, the "Ark of the New Covenant, clothed with purity instead of gold." In an ode to her, he wrote: "You are the Ark in which is found... the true Manna, that is, the Flesh in which Divinity resides."
The Council of Ephesus in 431 declared Mary was Theotokos (Greek for "God-bearer"), a title later translated as "Mother of God". Again we read Athanasius: "Should I compare you to the fertile Earth and its fruits? You surpass them, for it is written 'The Earth is My footstool' {Isaiah 66:1}. But you carry within you the feet, the head, and the entire Body of the perfect God."
The Israelites carried the Ark containing the Old Law with them on their Exodus, eventually carrying it in triumph to the Temple in Jerusalem. In these two windows, we see Mary carrying the New Law within her womb. In two other windows here at St. Martin's (The Presentation of Mary and The Wedding of Joseph and Mary), we will see the Blessed Virgin, the Ark of the New Covenant, enter into the Temple.
The God whom Earth and sea and sky
Adore and laud and magnify,
Whose might they claim, whose love they tell,
In Mary's body deigned to dwell.
O Mother blest! The chosen shrine
Wherein the Architect divine,
Whose hand contains the Earth and sky,
Came once in human form to lie:
Blest in the message Gabriel brought;
Blest in the work the Spirit wrought;
Most blest to bring to human birth
The long desired of all the Earth.
O Lord, the Virgin born, to you
Eternal praise and song are due,
Whom with the Father we adore
And Spirit blest for evermore.
- Venantius Fortunatus (530-609)
translated by John Mason Neale (1818-1866)