Truth in reviewing: I wrote extensively on Haimo's remarkable Ezechiel commentary and its sole surviving manuscript and fancied myself one of the very few if not only persons since the eleventh century to have read the entire commentary.  Now comes Roger Gryson's fine editio princeps, a new addition to the prestigious CCCM series, that will make Haimo and Haimo's commentary far better known. The Ezechiel commentary joins Gryson's earlier edition of Haimo's commentary on Isaiah.  Scholars of the Carolingian age produced about 150 biblical commentaries. Most late eighth- and early ninth-century commentaries digested patristic exegesis for its first great audience and consisted mainly of commentaries on commentaries. By the third quarter of the ninth century, exegetes the mettle of Angelomus of Luxeuil, Paschasius Radbertus, John Scottus (Eriugena), and Haimo of Auxerre overlaid their own grammatical, philosophical, or theological learning on the solid foundation the church fathers provided to craft commentaries that were at once more original and more engaged with the biblical text. Not much is known about Haimo, long confused with Bishop Haimo of Halberstadt (840-853), except that he was a monk and teacher at the important monastery of Saint-Germanus in Auxerre during the times of Louis the Pious and Charles the Bald (814-877), that he counted Heiric of Auxerre as one of his pupils, and that he served at some point as abbot of a little-known monastery at Cessy-les-Bois, 60 km. southwest of Auxerre. Throughout his career, Haimo commented extensively on the Bible. Many of his commentaries were printed in the nineteenth century in the Patrologia Latina from even older editions. The Ezechiel commentary has until now never been published and exists only in a high-quality manuscript, MS Paris, Bibliothèque nationale de France, lat. 12302, prepared by Abbot Helderic (989-1009) of Saint-Germanus. Medieval library catalogues from Cluny and Corbie record copies now apparently lost. Haimo's commentary, imperfecta since it ends abruptly with the last verse of book 39 of the 48 books of Ezechiel's prophesy, appears never to have circulated widely, in marked contrast to his other commentaries. It is difficult to account with confidence for its limited diffusion. I suggested that Haimo's pointed critique of the Carolingian church throughout the commentary disencouraged its dissemination, a view that Roger Gryson does not share. In his opinion the commentary's lack both of a preface and Haimo's comments on Ez 40-48 probably account better for its obscurity (17-18). Gryson also does not think that Haimo's death, as I wrote, explains why work on the commentary ended where it did, short of its putative goal. He more plausibly suggests that the pen would fall from the author's hand somewhere in midstream, rather than precisely and conveniently at the exact point of a major textual break where book 39 ends (in the Paris manuscript at fol. 122v) and just before the crescendo of Ezechiel's prophesy, his magnificent vision of Jerusalem and the new temple (13-14). Even Jerome hesitated to tackle Ezechiel's last books. Why Haimo might have remains a "mystery" (13-14). When Abbot Helderic ordered his copy of the commentary, perhaps from the original in his monastery's library (18), he had his scriptorium supply what was missing at the end from two sources. Folios 122v-140v continue with verbatim excerpts from Gregory the Great's homilies on Ez 40,1-47. Gryson did not include this "Gregory section" in the edition. When Gregory's homilies no longer supplied text, Helderic or the master of the Auxerre scriptorium, drew on a second source, an incertus auctor, to comment on the missing portion. These comments today extend only from Ez 40,48 to 42,3 where, indeed, they break off in mid-sentence at the end of the last line of the last folio of the truncated manuscript. Gryson included these comments, which exist nowhere else but in the Paris manuscript, in the edition as an appendix to Haimo's commentary (389-423).
The banal comments of incertus auctor, who was mostly interested in unpacking the significance of the dimensions of the temple and its furnishings, suffer by juxtaposition with those of his companions in the manuscript. Haimo's teaching on one of the most challenging books of the Bible is especially impressive. No other Carolingian exegete seems to have taken up the challenge, unless one counts Hrabanus Maurus, his contemporary, whose derivative compilation drowns its author beneath the weight of its two main sources. Haimo used his sources, chiefly the Bible itself, Jerome's Ezechiel commentary, Gregory's Ezechiel homilies and Pastoral Care, but also Ambrosius Autpertus, Augustine, Bede, Cassiodorus, Isidore of Seville, Josephus, Vegetius, and Vergil to fashion a fluid narrative that never submerges Ezechiel's voice or his own. The contrast with Hrabanus Maurus, who scissored-and-pasted large blocks from Jerome and Gregory one after the other to cobble together his Ezechiel commentary, could not be more striking. So, too, is Haimo's concern for his own times. The word hodie occurs often. As Gregory viewed Ezechiel's prophesy as a cautionary tale for sixth-century Italy, so Haimo urged his ninth-century students (snippets of the commentary were recorded in Heiric of Auxerre's Collectanea ) and his readers to do likewise. He referred comfortably to Saracens, as when he recorded their custom of baptizing their children "in the name of the Father, the Son, and the Holy Spirit" to ward off demons (168, lines 93-96). Northmen, Saracens, and Slavs sprung to mind when he thought of infidels outside the church (228, lines 414-416). Where Ezechiel foretold that God would cause "a great shaking in the land of Israel" (Ez 38,19) against Gog, Haimo recalled a similar commotio magna when Constantine brought together all the bishops of the world against Arius as well as a more recent one in the 790s when Charlemagne gathered together all the learned men of his empire against Felix of Urgel, a reputed heretic of the Carolingian age (379, lines 244-248). He also credited Charlemagne alongside Emperors Philip and Constantine with enlarging the Christian world (379, lines 263-264). When he thought of the rams of Ez 34,17 as boni doctores, he included Germanus, his monastery's patron, alongside Jerome and Augustine as examples (345, lines 220-221). These references to the world of Haimo's experience suggest that his comments about the contemporary church were deliberate and pointed. The real danger came from within the church, not from infidel outsiders. When Ezechiel excoriated Israel's leaders and called them lions and wolves who prey on their people, Haimo updated the reference to apply it to Carolingian bishops and priests whose greed not only afflicted the lives of the poor, but, what he thought worse, placed their souls in jeopardy (250, lines 335-251, line 348). Haimo expected contemporary bishops, abbots, and other clergy to be modern Ezechiels, watchmen, speculatores, warning their people and calling them to repentance. Instead, in Haimo's view, churchmen chosen for the wrong reasons, for their wealth and family connections, were unworthy watchmen and no better than murderers of their people (332, line 15-333, line 54). 
Notes: 1. John J. Contreni, "Haimo of Auxerre's Commentary on Ezechiel," in L'École carolingienne d'Auxerre de Murethach à Remi, 830-908, eds. Dominique Iogna-Prat, Colette Jeudy, and Guy Lobrichon (Paris: Beauchesne, 1991), 229-242; idem, "'By lions, bishops are meant; by wolves, priests': History, Exegesis, and the Carolingian Church in Haimo of Auxerre's Commentary on Ezechiel," Francia 29 (2002): 29-56.
2. Haymo Autissiodorensis. Annotatio libri Isaiae prophetae (Corpus Christianorum. Continuatio Mediaevalis, 135C; Turnhout: Brepols Publishers, 2014).
3. Add to the ninth-century testimonia of Haimo's commentary, gloss 351 of John Scottus (Eriugena), Glossae divinae historiae, eds. John J. Contreni and Pádraig P. Ó Néill (Florence: SISMEL/Edizioni del Galluzzo, 1997), 155-156. A ninth-century manuscript of the glosses supplements John Scottus's gloss on Ez 8,14 ("et ecce ibi mulieres sedebant plangentes Adonidem") with an aliter glossa drawn virtually verbatim from Haimo's commentary on the passage (132, lines 150-165).
4. Soundings turned up only two apparent minor editorial anomalies. The edition's "quod Christi caritas iungit" (39, line 500) does not report the manuscript's reading, "quos Christi caritas iungit" (fol. 8r, line 2). At 132, line 156, the manuscript's "p[ro]pt[er] uirilis m[em]bri magnitudine[m] (fol. 39r, line 13) appears as "propter uirilis menbri magnitudinem."