The Biden administration welcomed Hamas’s sudden declaration Monday that it accepted a ceasefire in Gaza — though the White House would not say what terms, exactly, Hamas had accepted. Hamas announced its agreement Monday with unspecified terms proposed by Egyptian and Qatari mediators — just hours after Israel began its attack on Hamas in its last stronghold of Rafah, in Gaza, by warning civilians to leave. Israel said that Hamas did not appear to have agreed to the terms of its proposal.