In the Indian Hindi-language horror film Tumbbad(2018), the cursed grandmother who is chained and locked in a room needs to be fed everyday in order to keep her sleeping. But if she is not fed on time, she wakes up.
Also she could be put to sleep easily by saying,
"Sleep otherwise Hastar will come".
Hastar is a demon god whose touch cursed grandmother.
This line was used on cursed people to put them to sleep. Feeding cursed people was not an easy task as they were some 100 year old physically deformed and mentally unstable. They were cursed with eternal life and always hungry for food.
My question is, why do they need to feed her everyday when she could be put to sleep by saying that one line?