It is found in Pāli and early Sanskrit sources but comes to prominence with the Yogācāra, for whom it denotes the latent energy resulting from actions which are thought to become ‘imprinted’ in the subject's storehouse-consciousness (ālaya-vijñāna).
Vasana literally means "perfuming," or "fumigation," that is, it is a kind of energy that is left behind when an act is accomplished and has the power to rekindle the old and seek out new impressions.
Through this "perfuming," reflection takes place which is the same thing as discrimination, and we have a world of opposites and contraries with all its practical consequences.
p.96[4] Lusthaus states that the Cheng Weishi Lun (Chinese: 成唯識論), a commentary on Vasubandhu's Triṃśikā-vijñaptimātratā, lists three types of vāsanā, which are synonymous with 'bija' or 'seeds':[5] Bag chags are important in Bonpo soteriology, especially the view of the Bonpo Dzogchenpa, where it is fundamentally related to the key doctrines of 'Primordial Purity' (Tibetan: ཡེ་ནས་ཀ་དག, Wylie: ye nas ka dag [note 2] As Karmay relates in his English rendering of the Bonpo text 'Kunzi Zalshay Selwai Gronma' (Tibetan: ཀུན་གཞི་ཞལ་ཤེས་གསལ་བའི་སྒྲོན་མ, Wylie: kun gzhi zhal shes gsal ba'i sgron ma) from the Tibetan:[6] "Some people doubt that if kun gzhi is pure from the beginning, it cannot be accepted as the ground on which one accumulates one's impressions (bag chags), but if it is the ground for storing the bag chags, it cannot be pure from the beginning.
[7] [note 3] Śrīmad Bhāgavatam (5.11.5) (also known as the Bhagavata Purana), a principal text for the Vaishnava tradition of Sanatana Dharma employs the term 'vasana': A satisfactory English rendering has not yet been sourced, but the import is that the 'imprinted-volitions-of-mind' (vāsanātmā), whether pious or impious, are conditioned by the Gunas.
[9] Writing from an Advaita Vedanta perspective, Waite refers to a model offered by Edward de Bono:[note 5] If you take a jelly, solidified and turned out onto a plate, and you trickle very hot water onto the top, it will run off onto the plate and leave behind a faint channel where the hot water melted the jelly.