|Sacristy of Saint Peter's Basilica, Rome|
He who goes about gossiping reveals secrets; therefore do not associate with one who speaks foolishly.—Proverbs 20:19
A practical reason for silence in the sacristy is that it gives the celebrant the opportunity to collect himself, to review his thoughts for the homily and to prepare himself to enter into the profound Mystery of the Holy Sacrifice of the Mass.
The silence of the sacristy helps protect the celebrant from unnecessary distractions.
The silence of the sacristy gives priest and servers the opportunity to discuss the Mass about to be celebrated. Together, they can refine their preparations by focussing their thoughts on the exact procedures required by the rubrics and review the timing of ritual gestures to help ensure a beautiful, reverent and seamless liturgical action that points to Christ acting in the Holy Sacrifice of the Mass.
A great performance of a symphony begins in the practice room and in rehearsal. Musicians study the score as individuals who then bring the fruit of their practice to rehearsal with their colleagues under the baton of the conductor who has also made a habit of preparing thoroughly for rehearsal. The combined efforts of the conductor and musicians to faithfully realize the score results in the performance. The Holy Sacrifice Mass, like great works of art, requires thorough preparation that begins with full respect for the text and ritual gestures and culminates in the prayerful rendering of the Divine Liturgy.
The silence of the sacristy helps to evoke a sense of the frequently under appreciated transcendent dimension of the Mass.
Silence all cell phones and other electronic devices. Emergencies excepted, there is no reason a cell phone should be active. If you cannot go an hour-and-a-half or two hours without texting or being connected to the internet, you may want to admit to a smartphone addiction and take steps to overcome a bad habit. Institute a daily 'cell phone siesta' to give yourself some healthy down time.
The preparatory prayers are rich in meaning and allude to or quote Scripture. Consider, for example, the prayer when donning the chasuble (St. Matthew 11:30):
O Lord, Who said: 'My yoke is easy and My burden light': grant that I may bear it well and follow after You with thanksgiving. Amen.
Almighty God and Father, help us to celebrate Your sacred mysteries with dignity, in truth and in spirit, so that by our example we may lead others to Your Son, our Lord Jesus Christ, Who lives and reigns with You and the Holy Spirit, one God, forever and ever. Amen.
Almighty Father, we give You thanks for the gift of the Holy Eucharist. Help us to serve well and always do everything to Your greater glory for the good of Your people. We ask this in the name of our Lord Jesus Christ Who lives and reigns with You and the Holy Spirit, one God, forever and ever.
There are some beautiful prayers that may be prayed (and are prayed, for example, in the Extraordinary Form) after the servers and priest have returned to the sacristy.