The need for, and indeed the importance of, commentary on the Holy Scriptures by the Church Fathers is expressed by Saint Peter:
"Knowing this first, that every prophecy of Scripture cometh not out of private explanation..." (2 Peter 1:20; Orthodox New Testament)
The same idea is captured in the Church canons. For example, consider the following (Rudder, pp. 313-314):
"We declare that the deans of churches, on every day, but more especially on Sundays, must teach all the Clergy and the
laity words of truth out of the Holy Bible, analyzing the meanings and judgments of the truth, and not deviating from the definitions already laid down, or the teaching derived from the God-bearing Fathers; but also, if the discourse be one concerning a passage of Scripture, not to interpret it otherwise than as the luminaries and teachers of the Church in their own written works have presented it; and let them rather content themselves with these discourses than attempt to produce discourses of their own, lest, at times, being resourceless, they overstep the bounds of propriety. For by means of the teaching afforded by the aforesaid Fathers, the laity, being apprised of the important and preferred things, and of the disadvantageous and rejectable, are enabled to adjust their lives for the better, and do not become a prey to the ailment of ignorance, but, by paying due attention to what is taught, they sharpen their wits so us to avoid suffering wrongly, and for fear of impending punishments they work out their own salvation.
(Ap. c. LVIII [the text reads "LVI", but this is, we can presume, an error of the typesetter]; cc. II, XVI of the 1st; c. XIX of Laodicea; cc. LXXIX, CXXXI, CXXXII, CXXXIII of Carthage; c. X of Peter; c. VI of the Faster.)
The Canon decrees that the Deans of churches, by which turn is meant preeminently the Bishops, but secondarily also the Presbyters, must teach all the Clergy and the laity every day in the week, and especially and above all on Sundays (or even other holidays). For on these days, since Christians are wont to rest from their manual work, they congregate in the churches and listen to the divine words. Consequently those teaching therein afford them additional benefit. But such men must not teach with their own words and thoughts, but with those of divine Scripture, without straying away from the definitions adopted and confirmed by Councils and the dogmas of the faith, or away from the teaching handed down by the God-bearing Fathers. And if at any time they repeat words of the Bible, they are not to explain them in any other way than as the teachers of the Church have explained them in their written works; and they must endeavour more to make headway by teaching the discourses of the divine Fathers than by composing sermons of their own, lest by employing thoughts and conceptions of their own, and being unable sometimes to understand things aright, they fall out of line with what is proper and the truth. For by learning things from this teaching of the doctrines taught by the Fathers, the laity learn what things are of advantage to their souls, and what are disadvantageous, and they accordingly change their mode of living from viciousness to virtuousness, and are freed from the darkness of ignorance. By paying attention, again, to that teaching, and hearing about the chastisements and punishments which bad persons are bound to suffer, for fear of these they abstain from vices and bring about their salvation. Besides this, however, c. XIX of Laodicea says that the Bishop must first give a didache (or "teachment") in the liturgy. Read also Ap. c. LVIII."
Note: these commentaries are no longer under copyright and have been collected here for convenience in html format from various, non-unique sources located on the internet (including http://www.tertullian.org and http://www.ccel.org). Links are also provided to pdf scans of the original texts. Generally speaking, it is also possible to purchase these commentaries in print form (contact Father Symeon if you are having trouble locating a source).
Note: these commentaries are under copyright. The content is generally of limited or restricted use, although still useful.
Commentary on the Sunday Gospel Lectionary Readings by Blessed Theophylact. A complete translation of Theophylact's Gospel commentary is available for purchase in text form (four volumes) from the same linked site where the lectionary commentary is provided. Here is what Bishop Ignatius (Ignatii) Brianchaninov, a renowned spiritual writer and monastic guide of nineteenth century Russia, has to say about this work:
“While reading the evangelists, the novice [or beginner] should also read The Explanation of the Gospels by Blessed Theophylact, Archbishop of Bulgaria. The reading of The Explanation is indispensable. It is an aid to the right understanding of the Gospel and consequently to the most exact practice of it. Moreover, the rules of the Church require that Scripture should be understood as the holy Fathers explain it, and not at all arbitrarily. By being guided in our understanding of the Gospel by the explanation of the holy Fathers, we keep the tradition of the holy Church.” (The Arena)