The manuscript is also important because it includes, as marginalia, some of the earliest known examples of written Old Welsh, dating to the early part of the 8th century.
Paleographic and stylistic similarities link it to Northumbria and Iona: the painting techniques resemble those of the Lindisfarne Gospels and the Book of Kells.
[8][1] However, in 1980, Wendy Stein made an extensive argument for Lichfield, viewing Wales as unlikely but Ireland and Northumbria as still possible.
[9] In 1996, by studying the type of paper, pigmentation, and style of text, researcher Pamela James concluded that the most likely place of origin for the manuscript was Lichfield itself.
Patterns of interlaced birds on the cross-carpet page (p. 216) strikingly resemble the ornament on a cross shaft from Aberlady, Lothian, a Northumbrian site of the mid-8th century: the author/artist of the book and the sculptor of the cross-shaft ornament may have had a similar source for their designs.
Other Insular illuminated manuscripts of possible Welsh origin include the Ricemarch Psalter and the Hereford Gospels.
Unfortunately, Matthew's incipit page is severely worn, appearing to have functioned as the manuscript's front cover for a number of years.
"[14] The "altar of St Teilo" has in the past been associated with the monastery at Llandaff but, as it has been determined that the third, fourth and sixth marginal inscriptions refer to lands within fifteen miles of Llandeilo Fawr, it is now thought that the book spent time there.
The second such inscription contains a unique example of early Welsh prose recording the details of the resolution of a land dispute.
Furthermore, it is very difficult to discern whether the same hand wrote the text, the gospels and dry-point glosses unless the letters show signs of a later development in style.
Dry-point glosses are etched into the vellum rather than produced by a smooth flow of a quill over a writing surface.
G. Charles-Edwards and H. McKee believe they have identified such features, elements of the letters in the glosses that appear to be a late-9th-century invention, in response to Carolingian minuscule.