Hridaya Rosary (Four Thorns Of Heart Instruction) is Book Four of "The Five Books of the Heart of the Adidam Revelation" series, and it is also one of Avatar Adi Da's 23 "Source-Texts" of the Way of Adidam. Avatar Adi Da has subtitled this primary "Source-Text" as: "The 'Late-Time' Avataric Revelation Of The Universally Tangible Divine Spiritual Body, Which Is The Supreme Agent Of The Great Means To Worship and To Realize The True and Spiritual Divine Person (The egoless Personal Presence Of Reality and Truth, Which Is The Only Real God)".As this subtitle indicates, Hridaya Rosary builds upon the Divine Revelation given by Avatar Adi Da in the previous 3 books in this series, and focuses on the esoteric Spiritual process of receiving and communing with His "Universally Tangible" Spiritual Transmission.