In the ancient time Sastra Jendra was only for certain gods, it was a top secret knowledge. In wayang stories, the supreme god Batara Guru had tought this knowledge to god Indra. A person who had accomplished the real meaning of the teaching of Sastra Jendra is a spiritually great person (Priyagung in spiritualism). Only a selective people could achieve Sastra Jendra, after passing successfully his/her Tapa Brata (spiritual ascetism).
In his classical works, Arjuna Sasrabahu, a poet of Surakarta Palace (1824), R.Ng.Sindusastra mentioned that “Sastra Jendra is a world secret” (Sastra Jendra wadining rat) Despite several comments circulated Sastra Jendra Hayuningrat Pangruwating Diyu is Sastra – knowledge; harjo – Raharjo – safe; Endra – god, king; yu – Rahayu – safe; ningrat – world, body; pangruwat – to be freed from; diyu – giant or buta – blind, cannot differentiate between good and bad.
Previously it was Sastra (Har) Jendra – a secret knowledge of gods, but at present it is becoming Sastra Ceta – a clear knowledge, showing a human being who is successfully doing his/her samadi, accepted by Gusti, he/she would see the reality (kasunyatan) for a person seeking for a reality, samadi is one of the most important thing to practice.
Achieving Sastra Jendra spiritually means: A human sees his/her real-self (kejatenira), his/her life is safe/perfect, able to ‘mamayu hayuning bawono’ – to embellish the world for the benefit of all creatures, knows the real knowledge of ‘Sangkan paraning dumadi’, the secret of circulation of life, from where it comes & where it goes. Of course it could happen only by the permit of Almighty God (Gusti Allah) as a blessing to our good, correct and continues spiritual efforts.
According to K. Suwardi, one of the followers of Sastra Jendra in Jogjakarta said that “Some kejawen people say this teaching can be achieved by those who perfectly understand the real meaning of Hanacaraka Javanese letters of characters. Based upon experience, I am of the opinion, the most suitable time to disclose the true essential purpose of Sastra Jendra is the night of 1st of Suro, the Javanese New Year, the holy day for Javanese”.
*From variety of resources