Ibn al-Shatir: which manuscript preserves the relevant theory?
His fourteenth-century planetary theory survives in several manuscripts. His separate work on the astrolabe does not alone prove that his Mercury model reached Copernicus.
What the critical edition shows
Penchèvre's 2021 critical edition of Ibn al-Shatir's Nihayat al-sul fi tashih al-usul establishes the Arabic text from several manuscript copies. The research case rates it a verified fact, at 98, that the work survives through a multi-manuscript Arabic tradition, which makes a census and stemma of the witnesses the next priority. Ibn al-Shatir, Erwan Penchèvre (critical editor) (2021) ↗
A witness from the author's lifetime
Saliba's 1987 study of Ibn al-Shatir's work uses the Bodleian manuscript Marsh 139 as its principal reference. The research case describes it as a lifetime-era witness copied in AH 768, about 1366 to 1367 CE, and lists a core set of five witnesses used in specialist work: Marsh 139, Marsh 290, Marsh 501, Hunt 547, and Leiden Or. 194. Journal for the History of Astronomy ↗
A manuscript is not the whole work
British Library Add MS 9598 is a composite astronomical-instrument manuscript containing Ibn al-Shatir's astrolabe treatise, the Takhbir al-ahbab. One section is dated 1497. The case notes it is not a witness of the planetary-theory text, and states a methodological rule at 99: an astrolabe or zij manuscript cannot be evidence for the transmission of his mature Mercury model unless the planetary content is actually present. British Library Archives and Manuscripts Catalogue ↗
What an early copy does and does not show
A second rule, also at 99: the existence of an early Arabic witness such as Marsh 139 constrains textual ancestry but does not establish any European read or access event before Copernicus. Where a text was copied is not the same as who read it.
Which work is in that manuscript?
If a library catalogue lists 'a work by Ibn al-Shatir', which questions would you ask of the entry before using it as evidence for a particular theory?