The Risāle-i Nūr Corpus ("The Book of Light Corpus" or "The Epistles of Light") is a thematic exegesis of the Qur'ān and, in many parts, it treats a great diversity of momentous issues pertaining to our contemporary world., The Book of Light mirrors the style of the Holy Qur’ān and runs parallel to it in its themes as well as the distinctive manner in which it treats them. The idiosyncratic, original, wide-ranging and often delightful nature of The Risāle-i Nūr Corpus has attracted literally millions of readers in Turkey and around the world, thanks to its unique style, which addresses modern minds in the most direct manner possible, whilst making the terminology and major questions of the classical Islamic sciences disarmingly accessible to all.

The Holy Qur'ān has four major themes and so does The Risāle-i Nūr as its tafsīr (exegesis). These themes are tawḥīd (the existence and oneness of God), nubuwwah (the prophetic mission), al-hasḥr (the resurrection and the afterlife), 'ibādah and ‘adālah (worship and justice).

This book in your hand, The Staff of Moses, is a translation of the “‘Asâ-yi Mûsâ Mecmû’asi” originally penned in Ottoman Turkish. The author compiled this book from amongst his various epistles of his corpus.

The Staff of Moses is comprised of three major parts.

The first part is called The Fruit Epistle which has eleven sub-sections each of which are titled as "an issue" (mas'ala). The second part is Hujjatu'llāhi'l-Bāligha (The Conclusive Proof) which has eleven sub-sections each of which is named as "the proof of faith (al-hujjatu'l- īmāniyyah)." The last part of the book is comprised of five additional epistles two of which are on Sincerity (Ikhlāṣ). The others are on Frugality (Iqtiṣād) and Gratitude (Shukr). The next epistle is another significant part of the book known as Khulāṣatu'l-Khulāṣah (The Essence of the Essence). It is the summary of The Supreme Sign (Al- Āyatu'l-Kubrā) which is itself a type of summary of The Book of Light.

The book ends with "The Letters of the Qur'ānic and Īmānic Service", the written exchanges between the author and his disciples regarding the epistles of The Book of Light, its virtues, its author and his service to Islām as well as other topics related to the Qur'ān and how to serve it.

The epistles that make up this book were written in various years from 1927 to 1945 and in different locations like Isparta, Afyon, and Denizli provinces of Turkey. Some of them were written while the author was in prison and some others were written in exile.