1. āyatana Sutta.-Once when the Buddha was staying in the Kūtāgarasālā in Vesāli, he preached to the monks a sermon on the six spheres of contact (salāyatana). The monks listened with rapt attention until Māra, making a terrible din, disturbed their peace of mind. The Buddha admonished the monks not to be led away by Māra, and the latter, discomfited, disappeared (S.i.112).
2. āyatana Sutta.-The four Ariyan truths are concerned with the six personal spheres of sense. Effort should be made to realise this. S.v.426.