Space category

Vairotsana instructing Pang Mipham Gönpo from a painting by Dugu Choegyal Rinpoche

Space category (Tib. Longdé; Wyl. klong sde) — one of the three categories into which Mañjushrimitra divided the Dzogchen teachings he received from Garab Dorje.

The root tantra of Longdé is called 'Longchen Rabjam'.

Khenpo Namdrol says:

Next, the inner category of space, the Longdé, is reckoned to consist of 20,000 ‘volumes.’ These can be classified into three: white space, black space, and variegated space, or they can also be categorized as nine spaces. From Shri Singha, Vairotsana received the Longdé pith instructions, and composed ‘the Vajra Bridge’, a scriptural text, which he transmitted in Tibet to Pang Sangyé Gönpo. Pang Sangyé Gönpo and the six successive disciples in his lineage left this world by dissolving into a body of light.