98 In addition, that this devotion flows from the very foundations of Christian teaching is clearly shown by the fact that the Apostolic See approved the liturgical feast before it approved the writings of St. Margaret Mary; for without exactly taking account of any private revelation from God, but rather graciously acceeding to the petitions of the faithful, the Sacred Congregation of Rites - by a decree of the 25th of January 1765, which was approved by Our predecessor, Clement XIII, on the 6th of February of the same year - granted the liturgical celebration of the feast to the Polish Bishops and to what was called the Archconfraternity of the Sacred Heart of Jesus at Rome. The Apostolic See acted in this way so that the devotion then existing and flourishing might be extended, since its purpose was "by this symbol to renew the memory of that divine love"(99) by which Our Savior was moved to offer Himself as a victim atoning for the sins of men.
Source: Haurietis Aquas (Vatican.va)