One would know nothing about this master if sMyo shul mkhan po did not point out in passing (p. 259) that the teachings he gave to Klong chen rab ’byams were at least partly based on the gter chos of Nyang ral Nyi ma'i ’od zer. This explains the silence of the Deb sngon (and, consequently, of all the historiographical literature that proceeds from it) about him.
With Tshong ’dus pa, “Khang dmar pa,” mThing ma Sangs rgyas grags ’od and rGyal sras Legs pa, we discover a fourth group of masters, who are neither those by who Klong chen rab ’byams was taught in his childhood and in bSam yas (although it is not impossible that they belong to this group), nor the learned monks of gSang phu, nor the eclectic tantric masters such as Karma pa Rang byung rdo rje, Bu ston, etc., but specialists in the special esotericism of the Ancient School (rNying ma) and in particular the gter ma – probably lay practitioners (sngags pa). It should be remembered, moreover, that Klong chen rab ’byams’ father was apparently versed in the revelations of Nyang ral Nyi ma’i ’od zer.
From Sangs rgyas grags ’od, our author received the transmissions and precepts of the bKa’ brgyad bde gshegs ’dus pa chen mo of Nyang’s gter chos, the gNam lcags ’ur mo, Vajrakīla, the Ḍākki gsang ba ye shes, mGon po legs ldan, sTag zhon, Seng zhon, etc. This time it is the study of the Nyang gter that would enable us to see more clearly about these transmissions; as for the life of this master, it is not impossible that all trace of him has vanished, if he left no written work and had no connection with the great monastic institutions or famous masters of that time.
Tülku Thondup specifies the identity of this character somewhat by calling him Myon thing ma ba Sangs rgyas grags ’od, which he does not seem to distinguish from a Myon thing ma ba Sangs rgyas grags pa. But this does not allow us to advance an inch further, because we do not know his sources.
There is no trace of this in the Ngo mtshar grub thob kyi rnam thar gter rgyud rin chen spungs pa’i rgyan, an interesting chronicle of the transmission of the gter chos of Nyang ral Nyi ma’i ’od zer, whose author, Rang grol rdo rje, seems to have been of the generation immediately after that of Klong chen rab ’byams (since he received teachings from rDo rje gling pa). Generally speaking, reading the texts devoted to the history of this or that lineage of the rNying ma pa gives the impression of an extraordinary scattering, of a multitude of schools claiming a common origin and a partly common textual corpus, but each pursuing its own destiny without real coordination or centralization.
With mThing ma Sangs rgyas ’od, we have reached the end of the list of masters at the beginning of all biographies. But for a while we thought I should add at least one more: sMon lam ’od zer. A curious sentence in the practice manual of The Self-Liberation in the Essence of the Mind (rDzogs pa chen po sems nyid rang grol gyi lam rim snying po’i don khrid, no. 209, p. 211) had misled me: “...he taught it to the learned and accomplished [master] bDe legs rgya mtsho, who expounded it to the Lord of the Dharma sMon lam ’od zer, who gave it to us...”. sMon lam ’od zer seemed to be the one from whom the author had received the precepts that are the source of rDzogs pa chen po sems nyid rang grol. The extreme difficulty in determining the origin of the instructions contained in this text, and the category to which they belong, seemed to be resolved, at least to some extent, by identifying this sMon lam ’od zer or, failing that, one of his predecessors in the lineage.
Ultimately, this is a simple misdirection occasioned by a slight corruption of the text: let us, in fact, examine the lineage of the Sems nyid rang grol as the rDzogs pa chen po sems nyid rang grol gyi lam rim snying po’i don khrid presents it: Samantabhadra; Amitābha; Padmasambhava; Ye shes mtsho rgyal; Śīlamati; mKhas grub bDe legs rgya mtsho; Chos rje sMon lam ’od zer; “myself” (bdag), namely, prima facie, the author of the text, Klong chen rab ’byams.
A first point cannot but attract our attention: when we know that the other parts of this trilogy are supposed to have been inspired directly by Ye shes mtsho rgyal (one of Padmasambhava’s consorts) to Klong chen rab ’byams, we are tempted to see in Śīlamati our author himself, since, after all, Śīlamati is nothing but the Sanskrit equivalent of his monk name (Tshul khrims blo gros). Thus we have a very expedient solution to our problem: bDe legs rgya mtsho is in fact a disciple of Klong chen rab ’byams, and sMon lam ’od zer a disciple of bDe legs rgya mtsho.
It sometimes happens, in fact, that texts containing elements relating to the lineage of transmission of a teaching are thus extended by posterity a few generations beyond the author, without this calling into question the general authenticity of the text. The process is simple: a master, who has to teach from a text, introduces a few handwritten marginal notes to recall precisely the detail of the transmission by which the tradition came to him. The posterity of this master then receives this annotated text, at a time when the author of the notes can no longer be questioned about the motives that led him to complete the text. The notes are then taken for corrections and, little by little, they are introduced in the xylographic editions. The corruption then becomes almost indistinguishable, since one can no longer distinguish at a glance between the original text and the additions.
This hypothesis is confirmed when one follows the trail, not of sMon lam ’od zer, but of bDe legs rgya mtsho, master of the latter. Indeed, in the prayer to the lineage of the Sems nyid rang grol (no. 270, pp. 234-235), the succession of masters is as follows: Samantabhadra in union; Amitābha in union; Padmasambhava in union; Ye shes mtsho rgyal; Dri med ’od zer (rGyal sras - ); bDe legs rgya mtsho (mkhas grub - ) ; Matimaṅgala (bya btang - ); Guṇaśrī (byang sems - ); bSam grub rgyal po (sprul sku- ); Nam mkha’ gZhon nu (’khrul zhig - ); Chos dbyings rdo rje (rGyal sras - ); Blo gros rgyal mtshan (mkhas grub - ); “our direct master” (rtsa ba’i bla ma, not specified).
The fifth character in the list, Dri med ’od zer, is clearly Klong chen rab ’byams. bDe legs rgya mtsho would therefore be the disciple of Klong chen rab ’byams, who, for the whole of this trilogy, would not claim to be from any human tradition. The rest of the lineage would come after Klong chen rab ’byams.
The final proof is found in several texts of the Zab mo yang tig, the sNyan brgyud gnad kyi mdo chings (no. 78, p. 17), the dGongs brgyud (no. 79, p. 27) and the gSang skor bla ma brgyud rim gyi gsol ’debs (no. 80, p. 30): bDe legs rgya mtsho always appears after sNa tshogs rang grol, i.e., Klong chen rab ’byams.
Comparison of the texts shows that the lineage of the Rang grol skor gsum after Klong chen rab ’byams is precisely the same as that of the Zab mo yang tig: dDe legs rgya mtsho, Matimaṅgala (aka sMon lam ’od zer), Guṇaśrī, sPrul sku bSam grub rgyal po, Nam mkha’ gZhon nu, Chos dbyings rdo rje, Matidhvaja aka Blo gros rgyal mtshan.
The question is definitely settled in view of the list of Klong chen rab ’byams’ disciples in the sMyo shul chos ’byung (p. 345), where bDe legs rgya mtsho is listed as the second most important disciple, under his full name, Zho thar gling pa mkhas grub bDe legs rgya mtsho (it is difficult to know whether mkhas grub is a part of his name or an epithet). We will come back later on to the disciples of Klong chen rab ’byams.
 [2021 addition : there are quite many texts containing these words within their title in the Yamāntaka corpus compiled mostly under the name of rGya zhang khrom rDo rje ’od ’bar in the Byang gter phyogs sgrigs (2015).]
 O rgyan gling pa discovered a practice cycle of the “protector riding a tiger” (mGon po stag zhon), but, as this gter ston is the almost exact contemporary of Klong chen rab 'byams, it is questionable whether this is the cycle that may not have been known at the time our author was taught by mThing ma Sangs rgyas grags ’od. [2021 : see, rather, sTag zhon sgrub thabs dbang bcas, n° 16 in rNying ma bka’ ma shin tu rgyas pa, vol. 20, p. 564 sq. – This texts, said to be based on gTer chen ’Gyur med rdo rje’s sGub thabs ’dod ’jo’i bum bzang, refers to the gNubs lugs and thus could be connected with the sTag zhon texts found in the ’Jam dpal tshe bdag cycle of the Byang gter phyogs sgrigs.]
 One could also take, in the same sense, the example of the bka’ ma'i mdo dbang gi bla ma brgyud pa’i rnam thar by rDo brag rig ’dzin Padma ’phrin las or the chapter of the Deb ther sngon po devoted to the transmission of the Klong sde’i rdor je zam pa.
 This is a synthesis of the three sections of the rDzogs chen, according to an oral indication by mKhas btsun bzang po rin po che (August 2001). But one still has to wonder where this synthesis comes from.
 Cf. Ph. Cornu, La Liberté naturelle de l'esprit (p. 239).