Cardinal Robert Sarah offers a few words for priests in his June 2015 essay for L’Osservatore Romano.
If the liturgy is Christ’s work, is it necessary for the celebrant to interject his own comments? We should remember that, when the missal authorizes an intervention, this must not become a profane, human speech, a more or less subtle commentary on current events, or a worldly greeting to the persons present, but rather a very brief exhortation to enter into the mystery (cf. General Introduction of the Roman Missal, no. 50). As for the homily, in itself it is always a liturgical act that has its own rules. “Participatio actuosa” in Christ’s work presupposes that we leave the profane world so as to enter into the “sacred action surpassing all others” (Sacrosanctum Concilium, 7). In fact, “we claim somewhat arrogantly to remain in the human sphere so as to enter into the divine” (Robert Sarah, God or Nothing [San Francisco: Ignatius Press, 2015], chapter IV).
A few comments from me …
First, just because offering a comment is possible at Mass does not mean that it is desirable.
Two, I don’t see the separation of the “sacred” and “profane” in SC 7. In fact, it might be a consideration in some contexts that the acts of prayer and liturgy and the sacraments bring a deeper level of holiness to things (if not people) who originate in the natural world. A greeting becomes ritual dialogue. Teachers become mystagogues. Human stories become parables. Food from field and vineyard …
That last citation is curious; I’d want to see the context. I think people view themselves as arriving at worship from the human sphere. God created us as physical and social beings, so I’d see the matter as one of perspective. Are we still offering a knee or a kiss as a remnant of aristocratic privilege? Do thrones and fancy clothes set apart a religious upper class, and is this more human than godly?
I would think some of this discussion hints at things distinguishable by context. And a sensitive and discerning pastor is surely the person best placed to deal with these questions.
Notes: I’ve used an “early” translation, attributed here to Michael J. Miller at Catholic World Report. I wasn’t able to find the original essay on the L’Osservatore Romano site.