lit. 'giving of the acquired', i.e. 'transference of merit.'
Though in the older texts very seldom mentioned (e.g. A.VII.50), it is, however, a widespread custom in all Buddhist countries. It is presumed that moral merit, especially that acquired through giving alms, can be transferred to others, apparently for the reason that one's own good deeds may become to others, especially to departed relatives and friends reborn in the ghost realm, an inducement to a happy and morally wholesome state of mind.
Transference of merit is advocated (though without mentioning the term patti-dāna) in the Tirokudda Sutta (Khp. and Petavatthu) and its Com. (Khp. Tr.).
It is one of the ten 'bases of meritorious action' (puññakiriyavatthu, q.v.), called there pattānuppadāna. (App.).
See 'The Doctrine of Reversible Merit by F. L. Woodward. Buddhist Review (London), Vol. I (1914), p. 38.