Claiming that a deceased's grave remains dark until food is served on their behalf

A: Preparing food for the people who attend the Funeral is an act of Bid`ah (innovation in religion) and an act of Jahiliyyah (pre-Islamic time of ignorance).As for the claim that the grave is dark and serving food by the people of the deceased and giving charity on his behalf before burying him will lighten the darkness of the grave before he goes into the grave, this has no origin and saying this is a matter of guesswork because it is a matter of the Ghayb (Unseen) which no one but Allah knows.