I listened to a talk by Ajahn Brahm, in which he stated (if I understood correctly) that in Vietnam there has been, at least at some point, a policy or rule within parts of the Saṅgha whereby lay practitioners were discouraged or explicitly forbidden from being taught deep meditative attainments, particularly the jhānas.
I am unsure whether this was an officially codified regulation, a directive from specific Saṅgha authorities, or a more informal but culturally widespread pedagogical convention, and I would appreciate clarification from those familiar with Vietnamese Buddhist institutions and history.
My question is primarily doctrinal and ethical:
On what ethical or Vinaya-based grounds could a restriction placed on lay practitioners (rather than on monastics) be justified?
Is the rationale related to concerns about insufficient sīla, the risk of attachment to meditative attainments, or the possibility of misinterpretation of jhāna experiences outside a monastic training context?
From the perspective of the Nikāyas, where jhāna is presented as the defining element of Right Concentration or Stillness (sammā-samādhi) within the Noble Eightfold Path, and where highly accomplished lay disciples are not entirely absent, how can limiting systematic jhāna instruction for laypeople be reconciled with the apparent universality of the path to liberation?
Does such a policy risk conflating institutional or pedagogical caution with ethical necessity, and if so, how is this distinction addressed within Dhamma–Vinaya reasoning?
Finally, if lay practitioners are structurally prevented from receiving instruction in deep concentration, does this effectively curtail their capacity for profound realization, including stream-entry or higher attainments, and how is this ethically justified in light of compassion and the Buddha’s statement that the Dhamma is taught openly and without a closed fist?
I ask this question with respect for cultural context and monastic discipline, but with a sincere interest in how access to liberating practices is ethically and doctrinally regulated within the Theravāda framework.