Charles himself said about 6 months ago that he was worried Israel would try to harm him because about a year ago he stopped supporting them over the genocide, so this isn't out of absolutely nowhere. My guess is that it was just a dogwhistle.

The fact that Israel is actually saying it, however? Like... Aight. If they said nothing I would have continued to disregard it, but Israel's statements are around the same credibility level as Russia's, so I kind of have to give credence to the possibility that the exact opposite of what they say is true...