Ven. Pius XII : The fourth end, (of the Holy Mass) finally, is that of impetration

Ven. Pius XII : The fourth end, (of the Holy Mass) finally, is that of impetration. Man, being the prodigal son, has made bad use of and dissipated the goods which he received from his heavenly Father. Accordingly, he has been reduced to the utmost poverty and to extreme degradation. However, Christ on the cross "offering prayers and supplications with a loud cry and tears, has been heard for His reverence."[70] Likewise upon the altar He is our mediator with God in the same efficacious manner, so that we may be filled with every blessing and grace.

MEDIATOR DEI

ENCYCLICAL OF POPE PIUS XII
ON THE SACRED LITURGY

71. Moreover, the appointed ends are the same. The first of these is to give glory to the Heavenly Father. From His birth to His death Jesus Christ burned with zeal for the divine glory; and the offering of His blood upon the cross rose to heaven in an odor of sweetness. To perpetuate this praise, the members of the Mystical Body are united with their divine Head in the eucharistic sacrifice, and with Him, together with the Angels and Archangels, they sing immortal praise to God[63] and give all honor and glory to the Father Almighty.[64]

72. The second end is duly to give thanks to God. Only the divine Redeemer, as the eternal Father's most beloved Son whose immense love He knew, could offer Him a worthy return of gratitude. This was His intention and desire at the Last Supper when He "gave thanks."[65] He did not cease to do so when hanging upon the cross, nor does He fail to do so in the august sacrifice of the altar, which is an act of thanksgiving or a "eucharistic" act; since this "is truly meet and just, right and availing unto salvation."[66]

73. The third end proposed is that of expiation, propitiation and reconciliation. Certainly, no one was better fitted to make satisfaction to Almighty God for all the sins of men than was Christ. Therefore, He desired to be immolated upon the cross "as a propitiation for our sins, not for ours only but also for those of the whole world"[67] and likewise He daily offers Himself upon our altars for our redemption, that we may be rescued from eternal damnation and admitted into the company of the elect. This He does, not for us only who are in this mortal life, but also "for all who rest in Christ, who have gone before us with the sign of faith and repose in the sleep of peace;"[68] for whether we live, or whether we die "still we are not separated from the one and only Christ."[69]

74. The fourth end, finally, is that of impetration. Man, being the prodigal son, has made bad use of and dissipated the goods which he received from his heavenly Father. Accordingly, he has been reduced to the utmost poverty and to extreme degradation. However, Christ on the cross "offering prayers and supplications with a loud cry and tears, has been heard for His reverence."[70] Likewise upon the altar He is our mediator with God in the same efficacious manner, so that we may be filled with every blessing and grace.