The Rhinoceros Sutra (Pāli: Khaggavisāna-sutta; Sanskrit: Khaḍgaviṣāṇa Gāthā; Gāndhārī: Khargaviṣana-sutra) is a very early Buddhist text advocating the merit of solitary asceticism for pursuing enlightenment (as opposed to practicing as a householder or in a community of monks or nuns).
Read more about Rhinoceros Sutra: Origins, Themes, Association With Pratyekabuddhas, Naming Controversy, Location in Buddhist Canons