Tirokudda Kanda: Do the dead really benefit from the gift given by the living?
In the Milindapañha the benefit of dedicating the merit of a gift to one's deceased relatives is limited to those who have been reborn as just one of the four sub-species of peta. It's explicitly denied that there can be any benefit to those reborn in hell, heaven, as animals or in the other three peta sub-species. Curiously nothing is stated one way or the other about those reborn as humans.

Rhys Davids' translation:

https://legacy.suttacentral.net/en/mil6.3.4

I.B. Horner's:
Pubba-peta-panha.pdf

Above post appeared in Dhamma Wheel.

https://dhammawheel.com/viewtopic.php?f=19&amp;t=32595&amp;hilit=Merit+transfer