6 But to all these duties, more especially to that fruitful Consecration which was in a manner confirmed by the sacred solemnity of Christ the King, something else must needs be added, and it is concerning this that it is our pleasure to speak with you more at length, Venerable Brethren, on the present occasion: we mean that duty of honorable satisfaction or reparation which must be rendered to the Most Sacred Heart of Jesus. For if the first and foremost thing in Consecration is this, that the creature's love should be given in return for the love of the Creator, another thing follows from this at once, namely that to the same uncreated Love, if so be it has been neglected by forgetfulness or violated by offense, some sort of compensation must be rendered for the injury, and this debt is commonly called by the name of reparation.
Source: Miserentissimus Redemptor (Vatican.va)