Exodus and Numbers, Windows 11 and 9

Window 11 sits just inside Window 13. The big side windows carry only odd numbers, so 13 is followed by 11. Its story begins with a child set adrift on a river: the Book of Exodus. You don't need to know the Bible, because the plot is simple. The Israelites had lived as slaves in Egypt for 400 years until one man led them out to freedom, and this window tells that epic escape. Most of the glass here is 13th-century, some 800 years old.

At the bottom, a baby floats on the Nile in a reed basket. Pharaoh had ordered every Israelite baby boy killed, so the mother entrusted her son to the river. The basket was found by none other than an Egyptian princess, who took the child in. He is Moses. Look closely at the reeds and you will spot a girl hiding and watching: Miriam, his older sister, making sure he is safe.

One tier up, the grown Moses tends sheep in the wilderness. Remember the long staff in his hand, because it is about to do remarkable things. Above it is the burning bush that is not consumed, and out of its flames God calls Moses for the first time: "Lead my people out of Egypt."

The middle of the window shows the ten plagues of Egypt: frogs, three days of darkness, flies. On the tenth and final night, the firstborn of every Egyptian household dies. The Israelites painted lamb's blood on their doorposts so that death would pass over their homes, so look for the blood-marked door.

The fourth tier is the climax, the Red Sea. The sea blocks the way ahead and the Egyptian army closes in from behind. At the last moment Moses raises his staff and the sea splits in two. The people cross between walls of water, and the pursuing army is swallowed up.

The top tier and the tympanum cover the forty years in the desert: manna, the food God sent down from heaven, and Moses receiving the Ten Commandments on Mount Sinai. Meanwhile, at the foot of the mountain, people have made a golden calf and are bowing to it, a calf on a pedestal with figures dancing around it. Moses, coming down in fury, smashes the stone tablets nearby. The heart of this window is the journey from slavery to freedom, and Moses' staff is at the center of it all.

Window 9 follows, with the mysterious events of the desert years in the Book of Numbers, a title that means counting the people. This window is unusual: its two lower tiers are almost entirely filled with coronation scenes, crowns placed one after another on the heads of tribal leaders. It shows a wandering crowd becoming an organized nation. Most of the glass is 13th-century.

Higher up comes the spy story. Moses sends scouts to see what the Promised Land is like, and the evidence they bring back is a masterpiece: two men carry a long pole on their shoulders, and from it hangs an enormous cluster of grapes, so big that one man couldn't carry it. It is visual proof of how rich the land is.

Near the top, close to the tympanum, is the window's most important scene, the bronze serpent. A snake coils around a pole, recalling how people bitten by venomous snakes in the desert were healed by looking at the bronze serpent. Later theologians saw the Cross here: just as looking at the serpent brought life, looking to Christ on the Cross brings life. It is a bridge between the Old and New Testaments.

Elsewhere, a man rides a donkey while an angel with a sword stands in front of it. The man can't see the angel and beats the donkey for stopping, and the donkey opens its mouth and asks, "Why are you beating me?" Notice that the 13th-century artist shows the donkey's words in a speech bubble, like a comic.

So Windows 11 and 9 have taken us through the Exodus and the forty years in the wilderness. Next is Window 7, the innermost on this wall, where the story reaches the threshold of the Promised Land.