The inscribed text is known as the Prajnaparamita sutra, or the Heart Sutra, which was translated into Chinese in the 7th century by the pilgrim monk Xuanzang on the orders of the Emperor Gaozong (r. 649-683 AD). One of the principal scriptures of the Madhyamika school of Buddhism founded by the great Buddhist philosopher Nagarjuna (c. 100-200 BC), the Heart Sutra expounds that through true wisdom, one may realise the emptiness of this world and so achieve Enlightenment.
An eight-page grey-green nephrite jade book inscribed with an excerpt of the Prajnaparamita Sutra, formerly the property of the Dowager Empress Cixi and now in the Chester Beatty Library, is illustrated by W. Watson, Chinese Jade Books in the Chester Beatty Libary, Dublin, 1963, no. 2, p. 24. Compare also two jade books inscribed with text from the Buddhist scripture known as the 'Ten Propitious Signs': the first sold in these Rooms, 5 November 1997, lot 1075; and the other from the Palace Museum, Beijing, included in the exhibition, Qing Legacies: the Sumptuous Art of Imperial Packaging, The Macau Museum of Art, 2000, and illustrated in the Catalogue, p. 142, no. 53. As in the case of the present example, the jade folios of the Palace Museum book are also bound with their corresponding rubbings, ibid.
Compare also secular-related jade books of the Qianlong period such as the spinach-green jade example inscribed with two versions of calligraphy from the Prose of the Loshen, Nymph of the Lo River, sold in these Rooms, 26 April 1999, lot 530; a book of four rectangular plaques inscribed with the title, Jingfu Ruidie, 'A celebration of fraternity', rejoicing the long life of Emperor Qianlong, sold in these Rooms, 30 April 2000, lot 571; and a ten-tablet spinach-green jade book dated to 1779, in honour of Qianlong's deceased mother, offered in the present sale, Important Jade Carvings from a Private Collection, lot 1212.