ANKARA   Israeli media on Tuesday quoted Israeli military sources as saying that the army is prepared to invade Rafah in the southern Gaza Strip in a matter of 72 hours if no deal on a cease-fire is reached. Egypt is hosting extensive negotiations with delegations from Israel and Hamas aimed at reaching a cease-fire in Gaza. The Israeli Ynet news website reported that the Israeli army's Chief of Staff Herzi Halevi approved the final plans for a military offensive in Rafah along with a plan for