That is an outrageous claim that requires hard evidence. So far, the only ones I’ve seen spread it are Hamas. Where on Earth did you pick it up?
Yeah it's a thing. You can find it if you look it up, but there.
To elaborate on the "intentionally" thing, after the attack itself Hamas soldiers holed up in Israeli homes with the hostages, thinking they'd be able to retreat because of course Israel wouldn't bomb them. Then the IDF bombed Hamas along with the hostages. You'll find this in the article, but just to sum up.
I'm honestly surprised you haven't heard of this; I thought it would be common knowledge on this site by now.