ཕ་རྒྱུད། མ་རྒྱུད།

The terms pitṛtantra (for Tibetan pha’i rgyud or pha rgyud) and mātṛtantra (for Tibetan ma’i rgyud or ma rgyud) are, in my view, ghosts words. This, however, does not mean that also Tibetan pha’i/ma’i rgyud or pha/ma rgyud are ghost words. The Tibetan pha’i rgyud or pha rgyud is an abbreviated or elliptical expression for rnal ’byor pha’i rgyud and is actually a rendering of yogatantra. The Tibetan ma’i rgyud or ma rgyud is an abbreviated or elliptical expression for rnal ’byor ma’i rgyud and is actually a rendering of yoginītantra. In Tibetan it would be quite legitimate to translate yogatantra as rnal ’byor pha’i rgyud and yoginītantra as rnal ’byor ma’i rgyud especially when there is a need to distinguish them, just as it is quite common to render bhikṣuvibhaṅga and bhikṣuṇīvibhaṅga as dge slong pha’i rnam and dge slong ma’i rnam ’byed, which in turn have often be abbreviated as pha’i rnam ’byed and ma’i rnam ’byed. In short, the Tibetan words pha and ma (also by the way yab and yum) in these contexts do not actually seem to mean “father” and “mother” but simply “male” and “female,” and hence I personally think it is not appropriate to translate yogatantra and yoginītantra as “father tantra” and “mother tantra.”

Addendum: Note the use of rnal ’byor pha rnams and rnal ’byor ma rnams (RZ1: 186).