Srimad-Bhagavad-Gita
FIRST CHAPTER — Dhritarashtra said:

^23:42 Verily, confusion of family is the hell of destroyers of family. (For then do) their own ancestors fall, deprived &c. This refers to the well-known Sraddha ceremony of the Hindus, the main principle of which consists in sending helpful thoughts to the dead relations, as well as to all the occupants of Pitri-loka (a temporary abode, immediately after death) accompanied with (to make the thoughts more forcible) concrete offerings. The poor are also fed to secure their good wishes.