Regarding Orthodox liturgical texts I read that Fr Florovsky was mostly self-taught through study of the service books.
Metropolitan Hilarion (Alfeyev) writes:
Liturgical texts as a school of theologyMay I now turn to the theological and dogmatic significance of liturgical texts. In my view, liturgical texts are for Orthodox Christians an incontestable doctrinal authority, whose theological irreproachability is second only to Scripture. Liturgical texts are not simply the works of outstanding theologians and poets, but also the fruits of the prayerful experience of those who have attained sanctity and theosis. The theological authority of liturgical texts is, in my opinion, even higher than that of the works of the Fathers of the Church, for not everything in the works of the latter is of equal theological value and not everything has been accepted by the fullness of the Church. Liturgical texts, on the other hand, have been accepted by the whole Church as a “rule of faith” (kanon pisteos), for they have been read and sung everywhere in Orthodox churches over many centuries. Throughout this time, any erroneous ideas foreign to Orthodoxy that might have crept in either through misunderstanding or oversight were eliminated by Church Tradition itself, leaving only pure and authoritative doctrine clothed by the poetic forms of the Church’s hymns.
This holds true above all for the daily cycle of services prescribed by the Orthodox Typicon, as well as for the weekly and yearly cycle found in the Octoechos, Lenten Triodion, Pentecostarion and Menaia, whose liturgical texts contain interpretations of and reflections on many episodes from the life of Christ and aspects of His teaching. In this sense one can say that liturgical texts are a “Gospel according to the Church”. During the ecclesiastical year, from the Nativity to the Ascension, the earthly life of Christ passes by the spiritual gaze of the faithful. Liturgical texts bring us close to Christ at His birth in Bethlehem, on Mount Tabor when He was transfigured, in the upper room on Zion during the Last Supper and on Calvary with the Crucifixion.
Liturgical texts are not simply a commentary on the Gospels since, in many cases, they speak of that which the Gospels pass over in silence. I would like to give an example from the Nativity service. The Gospel reading speaks very briefly of Christ’s birth: “The birth of Christ was thus: after His Mother Mary was betrothed to Joseph, before they came together, she was found to be with child from the Holy Spirit. Joseph, her husband, being a righteous man and not wanting everybody to know of this, wanted to let her go secretly” (Mt. 1:18-19). Much that happened at this event has remained hidden from us. For example, the narrative is silent about Joseph’s personal drama: we can only guess about his feelings and doubts, as well as about the words he uttered to his betrothed when he learned of her pregnancy. Orthodox liturgical texts attempt to recreate in poetic form a dialogue between Joseph and Mary:
Joseph says to the Virgin: Mary, what is this that I see in Thee? I am at a loss, astonished and horrified. Mary, what is this that I see in Thee? Thou hast brought me shame instead of honour, sorrow instead of rejoicing, reproach instead of boasting. No longer shall I endure the reproach of men, for I received thee blameless from the priest of the Lord’s temple, and what is this that I see?
When Joseph, O Virgin, was wounded by sorrow while going to Bethlehem, Thou didst cry unto him: why art Thou languishing in sorrow and confused, not knowing that all that has happened to me is part of the fearful mystery? But now lay aside all fear, knowing of the most glorious events, for in His mercy God hast descended to earth and is now in my womb, taking on flesh. When thou shalt see Him born, as He has willed, thou shalt be filled with joy and worship Him as thy Creator.
One may refer to such texts as “poetic invention” or “church rhetoric”, or one may see in them something more – a perceptive understanding of the feelings and experiences of those whose lives form Sacred History. Byzantine hymnographers made use of an extremely rich array of literary techniques since they spoke about that which ‘the eye has not beheld, the ear has not heard and has not entered the heart of man’ (1 Cor. 2:9), about mysteries beyond the limits of human reason, but grasped only by faith. There are many mystical truths in Christianity which, being difficult to explain in prose, are better served by poetry to help the faithful to understand.http://orthodoxeurope.org/page/12/1.aspx