Princeton University’s Digital Library has an interesting astrological manuscript from the famous 9th century Persian scholars Banū Mūsā brothers who lived and worked in Baghdad:
Ibn Shākir, Aḥmad ibn Mūsá, d. 873
Ibn Shākir, Ḥasan ibn Mūsá, 9th cent
Ibn Shākir, Muḥammad ibn Mūsá, d. 873
The book is called كتاب الدرج (Kitāb al-Daraj) or the “Book of Degrees“
It is a book of what each degree of the zodiac means (thanks to Ben Dykes for pointing me out to the online direction of the book and clarifying its content for me).
The red ink letters indicate the chapters. This one specifically says برج الحمل [burj alḥamal] which is the Arabic name for Aries. Arabic is written and read from right to left. So the first red ink letter beneath the chapter title is the Arabic letter alif ا which represents the number 1. Basically here the description of the first degree of Aries starts: آول درجة [awal daraja] or “first degree”.
The letter ب [bā] in several rows bellow represents number 2.
The letter jim in the last row represents three, etc.
It is basically description of what each degree of the zodiac means .
David Pingree speaks about the Banū Mūsā brothers in this article which you can read online and learn more about their life and work.