The Church does not apply indulgences to the souls in Purgatory, as she does to the faithful upon earth, by the tribunal of penance and absolution, but confers them simply by pious supplications and sacrifices offered in their behalf; thus they are relieved indirectly. The Holy Church opens her rich treasures of merit and satisfaction in proportion to the suffrages of the faithful, who offer expiation and fervent prayers to God for the relief of the suffering souls.
God has reserved to Himself the right to accept entirely, or in part, the satisfaction offered to any soul in Purgatory. This acceptance depends upon His holy and adorable Will, and, perhaps, in great measure upon the care of the soul to render herself worthy of the Divine Assistance during her earthly career. Besides, there may be some obligations neglected by the person who intends to gain the indulgence, owing to ignorance or forgetfulness on his part.
Therefore, we have no assurance whatever that an indulgence given by us to the holy souls has had the desired effect. Considering this, we should prepare most carefully, and fulfill all obligations required for gaining an indulgence. However, let us place, with entire confidence in the tender hand of Divine Mercy the application of indulgences to departed souls who are especially dear to us.
Prayer: Have mercy, O Lord, upon the suffering souls in Purgatory, mitigate the severity of Thy judgments; let the infinite merits of Thine only-begotten Son, and those of Thy saints, assist the holy souls, and deliver them from their sufferings. Through Christ, our Lord. Amen.
Special Intercession: Pray for the souls of those who neglected to gain indulgences for the souls in Purgatory.
Lord grant them eternal rest and let perpetual light shine upon them. May they rest in peace. Amen. (Three times.)
Practice: Offer all indulgences you may gain today, for the souls in Purgatory.
Invocation: My Jesus, mercy