Biden is talking specifically about a ground invasion, not the bombing Israel is doing in Rafah right now. Via CNN.com:
President Joe Biden said for the first time Wednesday he would halt some shipments of American weapons to Israel – which he acknowledged have been used to kill civilians in Gaza – if Prime Minister Benjamin Netanyahu orders a major invasion of the city of Rafah.
“Civilians have been killed in Gaza as a consequence of those bombs and other ways in which they go after...