It was very short notice.

Just before last Shabbat, President Donald Trump, finishing off his first week in office, signed an executive order banning immigrants from some countries for 90 days, and putting other restrictions in place, thus instituting the so-called “Muslim ban” for which he had called during his campaign, and causing havoc and heartache at airports around the world.

On Saturday night, Jewish women, many of whom had just learned about the situation after Havdalah, just after 6 o’clock, joined with Muslim and Christian women and started to organize.

On Sunday, at least 300 people gathered in Teaneck to rally against those executive orders. (Numbers are unclear; some participants think there were about 400 people but do not think it seemly to argue about crowd size.) The group that organized it, Teaneck Together, managed to get a police permit, lifted parking restrictions, speakers, and an impassioned crowd, using social media, their own friendship networks, and a shared sense of outrage.

“We did everything via phone and Facebook on Saturday night,” Shana Dworken, one of the organizers, said.

The Facebook group that was the rally’s seed was created right after Mr. Trump’s inauguration, by women who had listened to the speech, been appalled by its darkness and the implications that darkness evoked, and “decided that we had to do something,” Ms. Dworken said. “This was a way to do something. We couldn’t go to any of the marches” — particularly because they all were on Shabbat, and so would have required a great deal of planning and often intricate childcare arrangements — “so we started this group. There wasn’t a master plan, just a desire to support one another, and to build bridges. So we started adding people, with the intent that we could mobilize if something came up.

“But we didn’t realize that something would come up so fast. So Yasmeen Al-Shehab, Tovah Gidseg, and I started organizing.”

Ms. Gidseg, like Ms. Dworken, is Jewish; Ms. Al-Shehab is Muslim. One of the good things to have come out of the situation is that communities that had not been comfortable with each other — often for deep-seated and real historical reasons — have come to work together, and to build friendships that span the gaps between them.

The three women weren’t faced with that sort of ideological question on Saturday night, though. Instead, “this was a testament to the urgency,” Ms. Dworken said. “We are trying to do something, but we don’t have a plan or an infrastructure.” And, she noted, “this is all women-driven.”

Ms. Al-Shehab also was feeling shell-shocked by the election, she said, and even more by the darkness of Mr. Trump’s inauguration speech. She went to Washington for the march on Saturday, “and it was so amazing, so uplifting,” she said. “Friday I felt like I was at a funeral, like someone had died, but Saturday felt so hopeful. That lasted all day. And then every day after that has been a doozy.”

Last Saturday night, Ms. Al-Shehab was at a dinner party in Princeton “when I started seeing things from the Facebook group on my phone,” she said. “They said that they wanted to do a rally, and asked me what I thought the Muslim community will feel about it. I said that I don’t speak for the Muslim community — just for myself — but the people I know are pretty upset.” She signed on to help organize. Her job was to find speakers. She lined up Teaneck’s mayor, Mohammed Hameeduddin — that one was easy, he’s her brother — among many others, including newly installed Rep. Josh Gottheimer (D-Dist. 5), Rep. Frank Pallone (D-Dist. 6), Bergen County Freeholder Tracy Silna Zur, and the rabbi of Congregation Netivot Shalom, Nathaniel Helfgot.

“The feeling was very positive,” Ms. Al-Shehab said. “It was empowering.” And the healing was personal as well as political. “One of the issues of the Teaneck I grew up in, versus the Teaneck of today, is that today we are separate in our own little worlds,” she said. “Rabbi Helfgot said that we really have to talk about more than our own problems, more than things like yeshiva tuitions. Each community has something that we are focused on right now, but we have to get beyond that.

Congressman Josh Gottheimer addresses the crowd as Teaneck Mayor Mohammed Hameeduddin looks on.

Congressman Josh Gottheimer addresses the crowd as Teaneck Mayor Mohammed Hameeduddin looks on.

“On Saturday, I was pretty frozen. Paralyzed. I feared what that will mean for all of us. This guy” — Mr. Trump — “is really making good on what he said. What does a Muslim registry mean? It doesn’t mean that we’ll all have to register right away. It means that first he’ll ban people from those seven countries, and nobody will care. That won’t be overt enough. It will all happen subtly. They will label our civil liberty organizations as terrorist, and then the next thing will be that the person in the middle of the process of getting a green card will vanish. It will be covert and incremental, but all of a sudden, that person you used to know just won’t be there anymore.”

The rally gave her hope. Ms. Al-Shehab grew up in Teaneck and went to public school there, and she has chosen the same path for her children.

“My daughter, Zareena, is 13, and she spoke at the end of the rally,” Ms. Al-Shehab said. “She said to me, the day after the election, ‘Where is my place in Trump’s America? The president of the United States is supposed to protect me, but now I feel that they are coming for me.’” Zareena planned to talk about those feelings of exclusion and fear at the rally.

“But she didn’t say that,” Ms. Al-Shehab said. “I asked her why, and she said, ‘Because I didn’t feel that here. I didn’t feel that at all. Instead, I felt like I am going to be a leader one day.

“‘I was born in the hospital here, I go to school here, this is my country.’”

Mayor Hameeduddin was among the speakers. “I think that President Trump is really taking advantage of people’s fears,” he said. “He is putting together some draconian policies, and hoping that people will not question him, and instead fall in line with those policies. It is very interesting to see the spontaneous reactions to it. Without any organization, when people heard that other people were being detained at the airports, they rushed there to help.

“You have an awakening of opposition as we see what is and what is not acceptable in the American experience. There is a lot of room for debate and disagreement about foreign or economic or domestic policy, but something that no one in America could accept is people taking away other people’s rights.”

As for the Muslim ban, Mr. Trump might have backed off that description of his decision to ban refugees from seven majority Muslim countries — although not such majority Muslim countries as Saudi Arabia, Pakistan, Egypt, and Turkey, where terrorism is rife but where Mr. Trump seems to have done or have wanted to do business — but his close campaign advisor, New York City’s former mayor, Rudolph Giuliani, explained that in fact Mr. Trump did see it as a ban on Muslims. “That is something that no one should accept in America,” Mayor Hameeduddin said.

Mr. Gottheimer reported that he went to the rally with his children, after having spent the morning with them at the Jewish Federation of Northern New Jersey’s Super Sunday fund-raising drive. “It was hard to explain it to my 7-year-old,” he said. “I told her how my grandparents and great grandparents came to America, and that my wife’s grandparents fled the Holocaust. I tried to explain to her that we want people here who love America, and welcoming people here is part of what makes this America, that this is our fabric, and that of course the Jewish people know about that most particularly.

“Of course we have to be very careful about who we let into the country, but at the same time, when we start taking blanket actions against any group, that is completely counter to who we are as Americans.”

Not only is Mr. Trump’s policy misguided in its rejection of the American — and Jewish — ethos of welcoming the stranger, it also is likely to be counterproductive, Mr. Gottheimer said. “We have allies around the world, people who are supporting our efforts. It risks our security when you are cavalier in this way.

“We always have to balance security and our character, our freedom. It seems to me that we have completely upended this balance. In the way that Trump has handled this, he has upended it all in one fell swoop, and it has to be fixed. I am hopeful that he hears the country, and he takes swift action to repair the breach and to reverse this dangerous course that he is taking.”

Rabbi Lee Paskind of Congregation Beth Sholom in Teaneck, who has retired from the pulpit rabbinate and now works for the Conservative movement’s Rabbinical Assembly’s social justice commission, was at the rally. “It was really amazing,” he said. “It was a wonderfully diverse group. There was a large number of mostly modern Orthodox men and women, and about 30 people from our shul, and then a lot of people who appeared to be Muslim, and others who appeared to be Sikhs, and there were African Americans.

“The feeling was that it was a cross-section of Teaneck. It was very impressive to me that such a broad, diverse group would come together around this issue. It’s one of our new president’s bread-and-butter issues, but clearly there are a lot of people who oppose it.

“Speaking as a Jew, as a rabbi, I feel that we have a strong moral imperative to speak up for the vulnerable in our community and around the world,” he added. “The notion that we are going to allow displaced people from Syria and the adjacent countries to languish, that we are closing our doors, is unconscionable.

“What this president is doing — whether he is doing it or it is being done in his name — is frightening,” Rabbi Paskind said.

But despite the bleakness of the immediate future as the rally participants see it, something good is coming from it. That’s the inclusiveness of the response, both nationally and locally, Mayor Hameeduddin said. “The women of Teaneck, particularly the women of Netivot Shalom and other synagogues, pushed this forward and made it happen. They inspired me. I can’t process it now, but it really was an amazing day. Teaneck is really special. That is who we are.”

Ms. Dworken agreed. The group that put together the rally is interfaith on purpose, but that is more of a side benefit to its main goal — figuring out how to oppose what it sees as dangerous policies — than its major intent.

“We are moms,” she said. “Most of us also have full-time or part-time jobs, and a lot of responsibilities. We don’t have the intention of making this group something formal. We just want to see it grow.

“We don’t know what we will do next. We are not the ACLU. We do not have those resources. We would love to be able to direct people to those resources. We have to figure out the next step.” Echoing Mayor Hameeduddin, “we are still processing it,” she said. She is sure, however, that something will follow, and that the feeling of forward movement, and of friendship, will continue.