The Ofudesaki refers to the Scripture which Oyasama Herself took up a brush to write as a record of God the Parent's intention. It is made up of seventeen parts with 1,711 waka verses (which, with the exception of two verses, follow a 5-7-5-7-7 syllable pattern). We are told that Oyasama began writing Part I in January 1869 and put down Her writing brush with Part XVII in 1882.
According to the oral accounts of our predecessors, Oyasama would take up a brush whenever God the Parent intended it, even in the darkness of the night, and Her brush would automatically race across the surface of the paper to write the verses.
The Ofudesaki says that this world exists due to the intention of God the Parent. It also says that God will inform us by verse and the tip of Oyasama's writing brush when the human mind is not in accord with the divine intention (I:21-23). Along with revealing the divine intention, God the Parent, out of God's parental love and concern for the future of human beings, teaches us through the Ofudesaki the way we ought to handle our minds and devote ourselves to the path.
Further, the Osashizu gives us another explanation of why the Ofudesaki was written. To paraphrase its message: "Until now, you have forgotten much of what I have told you by word of mouth. Because you tend to forget, I have decided to put it in writing with the tip of My writing brush. Calling it the 'Tip of the Writing Brush,' may make it seem light, but it carries much weight. You should not treat it lightly in your minds. It is the very foundation of all talks, the very basis of the teachings" (refer to Osashizu, August 23, 1904). The Ofudesaki was written in the form of waka poems in order to make the teaching easier to understand and remember. Furthermore, metaphors such as "water," "path," and "dust" are used repeatedly in the Ofudesaki so that the core of the teachings can naturally settle in our minds. The Ofudesaki is the most important of the Three Scriptures and we should always keep it close at hand as our source of spiritual support.
On top of the Ofudesaki that is kept at Church Headquarters, Oyasama also wrote individual portions of the Scripture that She gave to several followers. These versions of the Ofudesaki are referred to as "exterior volumes" to distinguish them from the complete "original volume" that is kept at Church Headquarters (refer to The Life of Oyasama, the Foundress of Tenrikyo, pp. 84-85).
Further, among the portions of the Ofudesaki that Oyasama gave to followers, there are some verses that do not appear in the "original volume." Because these are verses that are not contained in its seventeen parts, they are referred as "unnumbered" (refer to The Life of Oyasama, p. 91).