[Question]{.underline}: Should one always announce a mystery when one announces a decade of the rosary for a special intention?
[Answer]{.underline}: The rosary is both a mental prayer and a verbal prayer. The completeness or integrity, but not the efficacy, depends upon observing both aspects of this wonderful prayer in honor of Our Lady. Consequently, just as the Our Father’s and Hail Mary’s ought to be recited correctly, and without undue haste, so likewise ought the mystery be announced that is to be meditated upon. Furthermore, it is also very beneficial to announce a special fruit or grace to be gained through the decade or rosary, for it helps the meditative aspect of the rosary when we understand what grace we are seeking to obtain.
It can and does frequently happen that when we recite a decade of the rosary for a special intention, such as vocations, that the particular mystery is not announced, especially if it is an additional decade. The reason for this is that the power of impetration is especially emphasized. However, it would certainly be preferable in such a case to announce a mystery, so that the recitation of this particular decade could also be a meditation as well as an intercession, and so that it could profit those who recite it as well as those for whom it is said. In this way, in fact, the decade will in fact be more efficacious, for the effectiveness of our prayers depends upon our conformity with the will of God, and this in turn is largely produced by meditation.
Let us, consequently, announce each decade as completely as possible, indicating the mystery, the grace requested, and the special intention (if there is one) for which it is offered.
Answered by Father Peter Scott, SSPX.