From Rigpa Wiki
Sutra (Skt. sūtra; Tib. མདོ་, do; Wyl. mdo) — the Sanskrit literally means ‘something that was heard from someone else’ and usually connotes ‘a discourse’.
- It refers to the discourses that the Buddha gave.
- ‘Sutra’, as distinct from ‘tantra’. The entire teachings of the Buddha can be distinguished as either sutra or tantra.
- One of the three collections of the Buddha’s teachings: Vinaya, Sutra (Tib. མདོ་སྡེ་, do de) and Abhidharma. Here, the Sutras are related primarily to meditation, and are said to be the remedy for the poison of anger and aggression.