Among the parts assigned to the priest, the foremost is the Eucharistic Prayer, which is the high point of the entire celebration. Next are the orations: that is to say, the collect, the prayer over the offerings, and the prayer after Communion. These prayers are addressed to God in the name of the entire holy people and all present, by the priest who presides over the assembly in the person of Christ.43 It is with good reason, therefore, that they are called the “presidential prayers.”
GIRM:
The gestures and posture of the priest, the deacon, and the ministers, as well as those of the people, ought to contribute to making the entire celebration resplendent with beauty and noble simplicity, so that the true and full meaning of the different parts of the celebration is evident and that the participation of all is fostered.52 Therefore, attention should be paid to what is determined by this General Instruction and the traditional practice of the Roman Rite and to what serves the common spiritual good of the People of God, rather than private inclination or arbitrary choice.
According to the 1997 document Ecclesiae de Mysterio, which was signed by 7 different dicasteries of the Holy See,
EM:
To promote the proper identity (of various roles) in this area, those abuses which are contrary to the provisions of canon 907 are to be eradicated. In eucharistic celebrations deacons and non-ordained members of the faithful may not pronounce prayers — e.g. especially the eucharistic prayer, with its concluding doxology — or any other parts of the liturgy reserved to the celebrant priest. Neither may deacons or non-ordained members of the faithful use gestures or actions which are proper to the same priest celebrant.
It is a grave abuse for any member of the non-ordained faithful to “quasi preside” at the Mass while leaving only that minimal participation to the priest which is necessary to secure validity.
The proper position for the celebrant during the Lord’s Prayer is “with hands extended. (GIRM, no. 152)”
You’ll notice that the same position for the Deacon is not the given at this point in the GIRM. You can, therefore, conclude that the
orans posture is not an option for the Deacon at this point.
If the
orans posture is implicitly not an option for the Deacon, then why do we assume that it is a legitimate option for the congregation?