Of the major Indian sources for this genre, clearly the most important is Śāntideva's epitome of the Mahāyāna, the Bodhicaryāvatāra, one of the so-called "Six Basic Texts of the bKa' gdams pas" (bKa' gdams gzhung drug; Thu'u bkwan: 106; BA: 268),9 which formed the foundation for the non-Tantric teaching of that school. Atiśa's own synoptic work, the Byang chub lam sgron ("A Lamp for the Path to Enlightenment"; Bodhipāthapradīpa) (BCLG) is also considered an important source (Thu'u bkwan: 106; Tucci, 1949, vol. 1: 99), as are such other frequently cited works as Nāgārjuna's Ratnāvalī (Hahn) and Candrakīrti's Madhyamakāvatāra (Huntington).

The influence of the BCA on the mental purification literature is obvious. As a practice-oriented synthesis of the bodhisattva path it provided a model for mental purification texts, and it is often quoted in these texts and their commentaries to elucidate key ideas. The Tibetan tradition is quite clear about this influence, crediting Śāntideva as a major figure in the transmission of the mental purification teaching (dNgul chu mThogs med: 210; Thu'u bkwan: 109). Of the nine chapters of the BCA, the one of most significance for the mental purification texts is the eighth, on the perfection of contemplation (dhyānapāramitā).

The central conception of the eighth chapter of the BCA, which is developed more fully in the mental purification literature, is "exchanging oneself and others" [page 248] (parātmaparivārtana, bdag dang gzhan du brje ba; see BCA 8: 120-131). This involves a thorough effort to realize the distress inherent in pride and self-centeredness, and the happiness and virtue which come from valuing others as strongly as one values oneself. This exchanging of oneself and others is closely related to "equality of oneself and others" (parātmasamatā, bdag dang gzhan du mnyam pa), an attitude of complete empathic identification with other sentient beings (BCA 8: 90-119; Buddhaghosa: 334). These are ideas that are fundamental to Buddhism as a whole (see Collins: 190-191), but which were given new emphasis and refinement of expression by Mahāyāna authors like Śāntideva.

Atiśa's BCLG is a précis of the entire Buddhist path, and the prototype for the "Stages of the Path" (lam rim) literature. The mental purification texts are often indistinguishable, even by Tibetan commentators, from works on stages of the path (TCKZB: 466), except in their succinct presentation, practical orientation, and concentration on one portion of the path, i.e., generation of an enlightenment-directed attitude (bodhicittotpāda, byang chub sems skyed; see Dayal: 58-64). The stages of the path contain the mental purification teachings within them,10 and the full stages of the path themselves can be presented within the structure of mental purification, as in a work by Tsong kha pa (the Tshig sbyor phun sum tshogs pa'i snyan ngag gi lam nas drangs pa'i blo sbyong in TKSB, vol. 22: 406-411).

A number of key points relevant to mental purification are mentioned in the BCLG; for example, in verse 5, Atiśa affirms the exchanging of self and other, stating that bodhisattvas seek to extirpate others' sufferings because of their total empathic identification with them (see also BCLG, v. 32, on mental purification). Another work by Atiśa, the Byang chub sems pa'i nor bu'i phreng ba (Bodhisattvamaṇyāvalī, Toh. no. 3951; "Jewel Rosary of the Bodhisattva"; see Rabten and Ngawang Dhargyey), which stands at the beginning of the LBLB collection (7-11), does not explicitly deal with the meditative praxis essential to the mental purification tradition, but is, rather, a homiletic exhortation to bodhisattva conduct in general, and much of its subject matter is included as supplementary material in the mental purification texts, e.g., in the instruction (bslab bya) section of the LBDDM.

All the above lends support to the Tibetan tradition (dNgul chu mThogs med: 207; Chattopadhyaya: 85) that mental purification, as a specific arrangement of Mahāyāna teachings in a form suitable for meditation, was an oral instruction (upadeśa, man ngag) originally given by Suvarṇadvīpī-Dharmakīrti11 to his pupil Atiśa, who in turn handed it down to his disciples as a private teaching (lkog chos) until it was publicly lectured upon by [Bya] mChad kha ba (1101-1175) and others (Thu'u bkwan: 109-110).[page 249]