Step 1: Context.
The concept of ‘Mahāsukha’ (Great Bliss) is central to Tantric and esoteric Buddhist traditions.
Step 2: Tradition.
It is specifically described in the Vajrayāna school, which emphasizes mystical practices, mantras, mudrās, and meditation aimed at attaining enlightenment through bliss and wisdom union.
Step 3: Analysis of options.
- (1) Theravāda: Focuses on early teachings, not on Mahāsukha.
- (2) Sarvāstivāda: An early Buddhist school, no concept of Mahāsukha.
- (3) Vajrayāna: Correct, Mahāsukha is a Tantric Buddhist idea.
- (4) Hīnayāna: A collective term for early Buddhist schools, no mention of Mahāsukha.
Step 4: Conclusion.
Thus, Mahāsukha is described in the **Vajrayāna tradition**.