7 In these letters, the pope explained the purpose and the importance of the mandate more clearly than the writers of that period who spoke of the mission "from the Apostolic See" or "of the Apostolic Pontiff." The terms he used are so grave and authoritative that we can scarcely find any more expressive: "The intended goal of your religious zeal and your proven faith have become manifest to us. They are such that they compel us to use you as a co-minister to spread the divine word which the grace of God confided to us." Then he praised his knowledge, his character, and his project. By the supreme authority of the Apostolic See which Boniface himself invoked, he solemnly concluded: "Therefore, in the name of the indivisible trinity and by the unshaken authority of Saint Peter, we affirm the purity of your faith and command that, by the grace and under the protection of God . . . you hurry to these people who are in error. Teach them about the service of the kingdom of God by acquainting them with the name of Christ, our Lord." Finally he warned him to maintain the rules of the Holy See concerning rites in his administration of the sacraments and to have recourse to the pope at any time. From this solemn letter, who would not recognize the good will and affection of the holy pope, and his paternal care toward the Germans to whom he sent one who was so dear to him?
Source: In Hac Tanta (Vatican.va)