The poem under this succinct title has the format of an oratorio, with the chorus singing the introduction and then the soloists taking their part, although I do not think it was every actually set to music. The shepherds, on their way back from the stable, sing to wake up the sun and tell him that tonight they saw a thing much more brighter than he; also, they saw by night something much better than they ever had seen by day. Then the two shepherds, named rather incongruously Tityrus and Thyrsis rather than Aaron and Isaac, take parts to describe the shining face of the child Jesus and how around him winter turned to spring. Tityrus scolds the world for not offering its God anything better than a cold stable and a manger, but Thyrsis corrects him: like phoenix building its own nest, God created the whole world and by extension also the place where he chose to be born. Clouds offer white bedsheets of snow, but these are too cold; the seraphim offer their fiery wings, but these are not pure enough. But the Virgin Mary’s breasts, in another metaphor uncomfortably too close to erotic poetry of the day, offer both warmth and the purity of snow. Then the full chorus takes up, welcoming the child Jesus in a series of oxymorons (“Summer in winter, Day in night” etc.) Even though Jesus is not born in riches, he has something far better than that: “two sister seas of virgin milk”. He is not welcomed to this world by vain courtiers but by humble shepherds, who nevertheless promise to come back in spring with its first gifts: flowers, lambs and doves.