In a response to questions by The Washington Post, a White House spokesperson said the president’s comments were based on news reports and claims by the Israeli government.

“The president based his comments about the alleged atrocities on the claims from Netanyahu’s spokesman and media reports from Israel, according to the White House.”

The Israeli army has said that it cannot confirm the claims, which were repeated on Wednesday by Israeli Prime Minister Benjamin Netanyahu’s spokesperson Tal Heinrich.

But Israeli military officials have told a number of media outlets that women and children were “brutally butchered in an ISIS way of action”.

https://www.aljazeera.com/news/2023/10/12/white-house-walks-back-bidens-claim-he-saw-children-beheaded-by-hamas#:~:text=The White House has walked,leaders at the White House.