Tib., zab lam
In a most general usage, this expression simply refers to what is more commonly known as the Mahamudra teachings and its lineage; reaching back in time via Milarepa and Marpa to Indian Mahasiddhas such as Naropa, Tilopa and Saraha.
In several instances, only recognizable by way of the context, zap lam is used as an abbreviation or 'short form' for a variety of terms or texts that are too long to keep saying or writing:
As seen in these abbreviations, the term zab lam can easily be qualified by adding other words; leading to related concepts such as
Contained in the last phrase, employing the term bliss and emptiness (bde stong), is a clear hint at the sexual nature of the practices associated with the so-called Anu Yoga fulfillment stage of the Inner Tantras. The Union of Bliss and Emptiness, symbolizing male and female, is synonymous with the more often encountered phrase Union of Skillful Means and Profound Cognition.
In this context, Zaplam refers to ritual techniques practiced, for example, by two of Padmasambhava’s female students and consorts (both with the Guru himself and with others). Judging from the available literature, Yeshe Tsogyal practiced with two partners in Bhutan, and Sakya Devi apparently did so in Nepal; which goes to show that these teachings, originally coming from India, got to be known throughout the Himalayas.
In this sense, Zaplam has been described as the yoga of coincident emptiness and pleasure
on the profound path
[Dowman, Sky Dancer, p. 249].
Here, sexual energy is used as motivation,
and desire as the object of meditation; thus becoming transformed into awareness and pure pleasure.
The technique, however, should only be carried out by adepts trained in the control
of all levels of energy, and especially - as Yeshe Tsogyal herself points out - in the
conscious re-direction of the male and female seed essences (Tib., thig-le; Skt., bodhicitta)
through the channels (Tib., rtsa; Skt., nadi) of the subtle body.
Even more evidence for the sexual nature of the Zaplam teachings and techniques is found on examination of the Tibetan term thab lam rather than zab lam.