Qudama ibn Ja'far

Qudama ibn Ja'far al-Katib al-Baghdadi (Arabic: قدامة بن جعفر الكاتب البغدادي‎‎; ca. 873 – ca. 932/948), also known as Abu'l Faraj, was an Syriac scholar and administrator for the Abbasid Caliphate, who converted to Islam.
Little is known with certainty about Qudama's life and work. He was probably born ca. 873/874, possibly at Basra, came from a Syriac Christian family and converted to Islam ca. 902–908. He held various junior administrative positions in the caliphal secretariat in Baghdad, and eventually rose to a senior post the treasury department. Various dates for his death have been supplied, ranging from 932 to 939/940 and 948.
Of his several books on philosophy, history, philology, and administration, only three survive:
the Kitab al-Kharaj (the Book of the Land Tax, in full form Book of the Land Tax and the Art of the Secretary), for which Qudama is chiefly known. Only the second half of the book, with four of its original eight sections, survives. It was written after 928 as a manual for administrators, and deals with the structure of the state and the army, as well with geographic details, including valuable accounts on the Caliphate's neighbours, especially the Byzantine Empire. It also included a now lost section on literary rhetoric.
the Kitab al-Alfaz (Book of Words) or Jawahir al-Alfaz (Jewels of Words), a compilation of synonyms and phrases for the use of poets and orators, as well as containing an introduction on the figures of speech.
the Kitab Naqd al-shi'r (Book on Poetic Criticism), an essay and guide on composing good poetry.