President Biden, in remarks Wednesday at the conclusion of a half-day visit to Israel, likened the events of October 7 to the Holocaust and pledged that America and its allies will not stand idly by and let anything like it happen again.

The world, he said, “watched then and did nothing,” referring to the Holocaust during World War II. “We will not stand by and do nothing again, not today, not tomorrow, not ever,” he said.

At the same time rockets were being fired from southern Lebanon into Israel, Mr. Biden said he will send Congress a request this week for what was described as an “unprecedented” package of military aid for Israel. “You are not alone,” he promised the besieged nation.

The president said he secured an agreement with the government of Prime Minister Netanyahu to allow humanitarian aid into Gaza, where hundreds of thousands of civilians have been displaced as Israel wages a campaign to wipe out the Hamas terrorists who attacked the country. Israel’s war cabinet said the aid will be limited to food, water and medicine for civilians in the territory and that any efforts to steer the aid to Hamas will be “thwarted.”

Mr. Biden also said America would provide some $100 million in humanitarian assistance for residents of Gaza and the West Bank.

He urged Israelis not to be “consumed by rage,” as he put it, but described the murder of at least 1,400 Israelis — only 700 of which have been identified as of Wednesday — as “pure, unadulterated evil” for which there is no rationalization. He said the attack was the equivalent population-wise in Israel to 15 of the September 11 attacks on the United States in 2001. He warned Israelis not to make the same mistakes that America made after those attacks.

“While we saw justice and got justice, we also made mistakes,” Mr. Biden said of the American response to 9/11. He praised the heroic efforts of the Israeli people to defend themselves from the Hamas terrorists and cope with the aftermath of the attacks.

“The State of Israel was born to be a safe place for the Jewish people. While it may not feel that way today… Israel must again be a safe place for the Jewish people.”

Mr. Biden had been scheduled to travel to Jordan following his trip to Israel, but a planned summit with Arab leaders there was abruptly canceled Tuesday night following an explosion at a hospital in Gaza that many in the region and the American press immediately blamed on Israel. Mr. Biden said Wednesday that the Pentagon provided evidence that the blast was caused not by an Israeli airstrike but by a misfired rocket originating at Gaza.

Mr. Biden’s Treasury Secretary, Janet Yellen, also announced Wednesday that it was sanctioning a group of 10 Hamas leaders and individuals in Gaza, Sudan, Turkey, Algeria, and Qatar connected to the terrorist network’s overseas financial network. Among those targeted are the managers of a Hamas investment portfolio, a Qatar-based financial facilitator with ties to the Iranian regime, a Hamas commander and a Gaza-based virtual currency exchange.

Secretary Yellen said America “is taking swift and decisive action to target Hamas’s financiers and facilitators following its brutal and unconscionable massacre of Israeli civilians, including children.”