The Rhinoceros Sutra has long been identified, along with the Aṭṭhakavagga and Pārāyanavagga as one of the earliest texts found in the Pali Canon. (Salomon, pp. 15-16) This identification has been reinforced by the discovery of a version in the Gandharan Buddhist Texts, the oldest Buddhist (and, indeed, Indian) manuscripts extant. It also exists in a Buddhist Hybrid Sanskrit version. The early date for the text along with its rather unusual (within community-oriented Buddhism) approach to monastic life have led some scholars to suggest that it represents a holdover from a very early stage of Buddhism. Themes
The sutra, which consists of a series of verses which discuss both the perils of community life and the benefits of solitude, and almost all of which end with the admonition that seekers should wander alone like rhinoceros. The verses are somewhat variable between versions, as is the ordering of verses, suggesting a rich oral tradition that diverged regionally or by sect before being written down. Association with pratyekabuddhas
In the 4th century Mahāyāna abhidharma work Abhidharmasamuccaya, Asaṅga describes followers of the Pratyekabuddha Vehicle (Skt. pratyekabuddhayanika) as those who dwell alone like the horn of a rhinoceros, or as a solitary conquerors (Skt. pratyekajina) living in a small group. Here they are characterized as utilizing the same canon of texts as the śrāvakas, the Śrāvaka Piṭaka, but having a different set of teachings, the Pratyekabuddha Dharma. Naming controversy
There is an ongoing dispute over whether the title, "sword-horn" sutra, is to be taken as a tatpuruṣa compound (a sword which is a horn) or as a bahuvrīhi compound (one who has a sword as a horn). In the former case, the title should be rendered "The Rhinoceros-Horn Sutra"; in the latter case, it should be rendered, "The Rhinoceros Sutra." There is textual evidence to support either interpretation. (Salomon, pp. 11-12)
In general, the Mahāyāna traditions in India took the title to refer to the image of an Indian rhinoceros, which is a solitary animal. The Theravāda tradition tended toward the "rhinoceros horn" interpretation, but there is some variance between Theravāda commentators, with some referring to the image of a rhinoceros rather than a rhinoceros horn. (Salomon, p. 13) Location in Buddhist canons
In the Pali Suttapitaka, this sutta is the third sutta in the Khuddaka Nikaya's Sutta Nipata's first chapter (Uragavagga, or the "Snake Chapter," named after the chapter's first sutta), and thus can be referenced in the Pali canon as "Sn 1.3." For a complete translation of the Pali text, see Thanissaro (1997).