Sanskrit Buddhist literature refers to Buddhist texts composed either in classical Sanskrit, in a register that has been called "Buddhist Hybrid Sanskrit" (also known as "Buddhistic Sanskrit" and "Mixed Sanskrit"), or a mixture of these two. Several non-Mahāyāna Nikāyas appear to have kept their canons in Sanskrit, the most prominent being the Sarvāstivāda school. Many Mahāyāna Sūtras and śāstras also survive in Buddhistic Sanskrit or in standard Sanskrit.
During the Indian Tantric Age (8th to the 14th century), numerous Buddhist Tantras were written in Sanskrit, sometimes interspersed with local languages like Apabhramśa, and often containing notable irregularities in grammar and meter.
Indian Buddhist authors also composed treatises and other Sanskrit literary works on Buddhist philosophy, logic-epistemology, jatakas, epic poetry and other topics. Sanskrit Buddhist literature is therefore vast and varied, despite the loss of a significant amount of texts. While a large number of works survive only in Tibetan and Chinese translations, many Sanskrit manuscripts of important Buddhist Sanskrit texts survive and are held in numerous modern collections.
Buddhists also wrote secular works on various topics like grammar (vyākaraṇa), poetry (kāvya), and medicine (Ayurveda).
History
History in India
The Buddha's teaching on scriptural language
The earliest Buddhist texts were orally composed and transmitted in Middle Indo-Aryan dialects called Prakrits. Various parallel passages in the Buddhist Vinayas state that when asked to put the sutras into chandasas the Buddha refused and instead said the teachings could be transmitted in sakāya niruttiyā (Skt. svakā niruktiḥ). This passage was interpreted in different ways in India, China and in Western scholarship. Various translations and passages in Indian Vinaya works interpret chandasas as referring to the language used by Brahmins, i.e. Vedic Sanskrit and sakāya niruttiyā as referring to local vernacular languages or dialects. This view has also been taken by various modern scholars like Franklin Edgerton.
However, the Sarvāstivāda Vinaya texts state that chandasas does not refer to Sanskrit itself, but to a specific Vedic intonation used to chant the Vedas. Scholars like Sylvain Lévi have seen this as an attempt to suppress the Buddha's rejection of Sanskrit but other scholars support the reading of the term nirutti as meaning "intonation", "recitation" or "chant."
The British philologist K.R. Norman defines nirutti as "synonym" or "gloss". Bryan Levman notes that the term can also mean "explanation of words," "grammatical analysis," "etymology," "pronunciation," or "way of expression" according to the Pali English Dictionary. Levman argues that numerous usages of the term in the Pali canon support the idea that the term here means a description or "explanation, not necessarily etymological, of the meaning of a word or text." According to the Levman, the famous Vinaya passage on language can be seen as meaning that the Buddha did not approve of certain monks who were using their own terms, expressions and explanations instead of the special terminology developed by the Buddha to explain his teachings. When some monks told this to the Buddha, they recommended that the Buddha's word be put in chandasas (Vedic meters and chanting forms), but the Buddha refused and said the teaching should merely be transmitted using his "own terminology" (sakāya niruttiyā).
Sanskritization and adoption of Sanskrit
Early Buddhists used a variety of related Middle Indic prakrit dialects. The Theravada tradition eventually adopted one form of Middle Indic, called Pāli, as its canonical language and the Pali Canon was written down in this language in the 1st century BCE in Sri Lanka. However, in North India and Central Asia, Buddhist texts were transmitted in other prakrits like Gandhari, Northern Buddhist texts were also often sanskritised in varying degrees and translated into other dialects and languages.
Furthermore, from the third century on, new Buddhist texts in India began to be composed in standard Sanskrit. Over time, Sanskrit became the main language of Buddhist scripture and scholasticism in North India. This was influenced by the rise of Sanskrit as a political and literary lingua franca of the Indian subcontinent, perhaps reflecting an increased need for elite patronage. Because of this, many manuscripts from Northern Buddhist traditions are often in Sanskrit, either classical or a non-standard form, often called Buddhist Sanskrit or Buddhist Hybrid Sanskrit (BHS). BHS is an intermediate or mixed language that contains elements of an unknown Middle Indic Prakrit and standard Sanskrit.