Let’s wrap up the epilogue, and with it, this notable document in the history of liturgy. First an urging to obedience:
208. Let Us remind all that they must generously and faithfully obey their holy pastors who possess the right and duty of regulating the whole life, especially the spiritual life, of the Church. “Obey your prelates and be subject to them. For they watch as being to render an account of your souls; that they may do this with joy and not with grief.”[Heb. 13:17]
An encouragement to unity, inspired partly by the vision of heaven and the role of the Blessed Mother:
209. May God, whom we worship, and who is “not the God of dissension but of peace,”[1 Cor.14:33] graciously grant to us all that during our earthly exile we may with one mind and one heart participate in the sacred liturgy which is, as it were, a preparation and a token of that heavenly liturgy in which we hope one day to sing together with the most glorious Mother of God and our most loving Mother, “To Him that sitteth on the throne, and to the Lamb, benediction and honor, and glory and power for ever and ever.”[Rev. 5:13]
And a final note of confidence:
210. In this joyous hope, We most lovingly impart to each and every one of you, Venerable Brethren, and to the flocks confided to your care, as a pledge of divine gifts and as a witness of Our special love, the apostolic benediction.
Given at Castel Gandolfo, near Rome, on the 20th day of November in the year 1947, the 9th of Our Pontificate.
PIUS XII
What do you think? It’s been a long journey with Mediator Dei, which you can access on the Vatican web site. The urging to participation (MD 192, 194, 199) was more of a surprise to me, given the tone in many 1962/1970 liturgical discussions. The formality of tone, even compared to John Paul II, also struck me. This was a totally different age for Roman Catholicism. After years of reading the conciliar documents, the post-conciliar liturgy legislation, and the modern efforts in evangelization, this is a totally different culture, perspective, and outlook.
I have to admit my relief that this document is completed. But in my own reflection, I am confronted with the need to be grateful for the faith witness of this pope. Liturgy was clearly close to his heart, and likely even more, a deeply Catholic spirituality. And of note is his desire that all of the faithful partake of the sustenance of the spirituality that clearly sustained him through the war years.
Any final comments, my friends? If this has been a favorite document of yours, I hope I have not occluded it too badly. Take the last word, if you wish …
Catholic Sensibility 
I would just like to remind readers of the context: this is just 3.5 years after the liberation of Rome, and 2.5 years after V-E Day. Think of how much ruin was around, and the many millions of displaced persons. Consider also how Piux X’s liturgical and sacramental reforms immediately preceded Europe’s self-destruction in World War I.
What I surmise is Providential in this arc is that God was prompting his servants to pay more attention to the feeding of the flock in the liturgy and sacraments, because it was that flock (rather than the princes of the Church) that was going to be rebuilding the world in a new material creation so that a new spiritual creation might also have a opportunity to take root as well.
As always, I enjoy the review of documents. Thanks for the series.