I am a theologian and church historian, so I tend to have quite a bit of studies behind me, thank you. What I was curious about was where your sources came from that stated that both early monastics and laity (3rd, 4th, even 5th century) used Marian devotions in their prayers. Or where it states that the Desert Fathers and Mothers had ANY impact on the prayers of the laity.
In Western monasticism, we can say for certain that the Rule of St. Benedict (circa 6th century), did not mention the Blessed Virgin Mary even though it quotes scripture abundantly. Nor for that matter does it directly mention the Mass. It only does so in an oblique way talking about ordaining monks for service at the altar or taking in already ordained priests as monks.f We do know that Mass was not daily back then, so the Mass did not count towards the number of times the monks were to gather to pray. Now many monasteries do include the Mass in the “count”.
St. Benedict gives us one of the first clear schemas for the Divine Office. He describes it in detail over 12 chapters, detailing which psalms were to be said when, when each Hour was to be said, how to account for shorter nights in summer, where to place the hymn (which he called the “ambrosian”), whether to use antiphons or not (not if the community is small); one could write a thesis about it. His schema required reciting 250 psalms a week, obviously with many repetitions.
And then he adds one curious little statement at the end, that if monks aren’t satisfied with this arrangement, that they could devise their own as long as they say all 150 psalms in a week
For those monks show an exceedingly slothful service in their devotion who, within the course of a week, sing less than the entire Psalter with the usual canticles, since we read that our holy Fathers resolutely performed in a single day what we tepid monks but hope to achieve in an entire week.
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Certainly monastics did develop a Marian devotion at some point, many monasteries having been dedicated to (and named for) Our Lady.
As for Jesus, he most certainly did not “pray” the Rosary. He lived it. It is His life that the Rosary is about. He prayed the Psalms and He prayed the Father directly (cf. the Garden of Gethsemane; on the Cross…)
Personally I find that praying the LOTH makes praying the Rosary a bit redundant… so I rarely pray the Rosary. At the abbey I’m associated with, they do have community Rosary but it isn’t compulsory from what I’ve been told. The abbey does use a monastic version of the LOTH that prays all 150 psalms in a week.