The Ben Ish Chai has a Halacha that might not be so applicable by Chanukah but has applications outside of Chanukah. He discusses oil that is placed under a bed where somebody sleeps. It seems that was where some stored their oil. He holds that this oil is Pasul (not kosher), and it is not worthy to use this oil to light the Menorah of Chanukah. According to the Ben Ish Chai in Parashat VaYeshev, Halacha 12, when you leave food under a bed, there’s a bad spirit on it, and it becomes possessed with that spirit and it becomes inedible. And since food is considered inedible so then it’s also considered improper for the Mitzvah of candle lighting also. If you can’t eat from there, so then you can’t use oil from there for the Mitzvah. He quotes a Pasuk [listen to the audio clip for the exact quote,] that basically says that if you wouldn’t bring food from under a bed to a human being, and as such you can’t bring this oil to Bore Olam as a Mitzvah. So the Ben Ish Chai’s opinion is quite clear. Not only does that food (including oil) left under a bed become unviable for a Mitzvah, but it becomes also not viable for eating purposes.
Chacham Ovadia is also concerned about the bad spirits on foods left under a bed, and he holds Lechatchila, that one should not eat those foods. However, he writes that there are some opinions that say this only is talking about where you put the food on the actual ground itself which is where the bad spirit is able to posses the food. But our homes either have a rug or tile where you are not actually putting it on live ground. So he says if it’s a situation of Hefsed Merubah, where if discarded you would suffer a great loss, then you would be allowed to eat it, and for that matter you would be allowed to use oil from there for candles of Chanukah. (Halichot Olam, Helek 1, Page 67.)
Now for us, Hefsed Merubah is not so applicable. I am bringing this Halacha to your attention because it is quite common for children to sometimes take their snacks and put it underneath their bed. They put it there sometimes before they go to sleep, or sometimes because they want to hide their candies. Those snacks are not considered Hefsed Merubah, and therefore, one should not let their children eat those foods because they have a bad spirit on them. You should discard them.
Chacham Ovadia was talking about where you have a whole carton of goods underneath the bed. That’s considered Hefsed Merubah (a large loss), so there already he’s lenient to use the oil and use it for candles of Chanukah.
So the Halacha, if oil is left underneath a bed, it would still be Kasher for candle lighting of Chanukah. However, when it comes to eating, only when it is Hefsed Merubah (suffering a great loss), would it be permissible to use, but in all other cases eating this food would be forbidden.
