Book of Hours were prayer books designed for the laity, but modeled on the Divine Office, a cycle of daily devotions, prayers and readings, performed by members of religious orders and the clergy. Its central text is the Hours of the Virgin. There are eight hours (times for prayer ): Matins, Lauds. Prime, Terce, Sext, None, Vespers and Compline. During the Middle Ages, the leaves making up a Book of Hours were written by hand on expensive parchment and beautifully illuminated with jewel-like pigments and gold leaf. These illuminated manuscripts combined the collaborative efforts of an array of highly skilled craftspeople; requiring the joint labors of the parchmenter, professional scribes to write the text in Gothic script, artists to illuminate the pages with decorations, and masterful binders to complete the process.

Superb vellum leaf from a Book of Hours with the text in a bold gothic book hand with twelve illuminated initials and seven line fillers in red, blue and burnished gold ink. The text includes part of Isaiah 38 and beginning with the capital "E" on recto translates as:

I said: In the middle of my days, I will go to the gates of Hell. So I sought the remainder of my years.
I said: I will not see the Lord God in the land of the living. I will no longer behold man, nor the habitation of rest.
My longevity has been taken away; it has been folded up and taken from me, like the tent of a shepherd.
My life has been cut off, as if by a weaver. While I was still beginning, he cut me off. From morning until evening, you have marked out my limits.
I hoped, even until morning. Like a lion, so has he crushed all my bones. From morning until evening, you have marked my limits.
I will cry out, like a young swallow. I will meditate, like a dove. My eyes have been weakened by gazing upward. O Lord, I suffer violence! Answer in my favor.

References:

Condition: A

A bright leaf with just a hint of marginal soiling.