Yohn said a more comprehensive, written version of his ruling would be filed later. He said he was inclined to leave the injunction blocking the new law in place for a year to give the Nutter administration and homeless advocates time to find a solution.
Nutter's ordinance, which bans public feedings of groups of more than three people in any city park, took effect June 1.
At the time, the mayor announced that as a transition, the city would let religious and homeless services groups distribute food in front of City Hall's north portal. At the end of the one-year transition, Nutter said, all homeless people would be fed from at least four indoor facilities around Center City.
Enforcement of the ordinance has been enjoined since a legal challenge was filed, and groups that fed homeless people for years along the Parkway, between 16th and 20th Streets, have continued doing so with impunity.
Members of the four religious groups that fought the ordinance broke into applause after the hearing. All vowed to continue feeding homeless people on the Parkway near the Free Library.
"Glory to God," said the Rev. Cranford Coulter, pastor of the King's Jubilee, a Souderton-based ministry that has distributed food to the homeless since 1989. King's Jubilee was one of the groups that challenged the feeding ban's constitutionality.
Coulter had enough time to hand a reporter a car-bumper magnet - "Serving the homeless is not a crime" - before rushing to leave the federal courthouse in Center City.
"I've got to get back and get ready," said Coulter, explaining that he planned to come back to 18th and Vine Streets by 8 p.m. Thursday for his group's regular prayer service and distribution of food.
Paul M. Messing, a Center City civil rights lawyer who challenged the ordinance with the Philadelphia chapter of the American Civil Liberties Union, said Yohn's ruling "demonstrated that the city has failed to come up with any good reason to stop religious groups from doing - and what they will continue doing - on the parkway."
Sister Mary Scullion, founder of Project H.O.M.E. and an expert on homeless issues, called the ruling "a ray of hope in very, very difficult and troubling times for those who are poor and homeless."
Scullion had supported Nutter when he announced the ban in March. As a witness for the plaintiffs, Scullion told Yohn she still supports the idea in principle but did not think there were enough facilities to feed the estimated 175 people who live outside along the parkway, as well as other poor people who are simply hungry.
One homeless man off Logan Square Thursday echoed Scullion's comments.
"There's families that rely on that food," said Christopher Janney, who said he was homeless until moving in with a friend last month. "They come out here for their meals, they take it home for their kids' breakfasts, lunches, dinners the next day. It isn't just the homeless."
Scullion also warned that impending state budget cuts to general assistance benefits could put more people on the streets and make more people rely on free food distributions.
Nutter said, "Certainly we are disappointed in this."
He added that the city is "committed and not deterred at all in our efforts to address the many challenges people face when they are homeless."
The mayor and City Solicitor Shelley Smith stressed that Yohn's ruling was only temporary until he issues a formal opinion.
Nutter called the judge's findings the "earliest of possible stages. . . . I would characterize it as the preliminary of the preliminary."
Four groups - Chosen 300 Ministries, the Welcome Church, King's Jubilee, and Philly Restart - sued challenging the ordinance.
Nutter administration officials have argued that the public feedings on the Parkway - part of 9,200-acre Fairmount Park - rob homeless people of dignity, have the potential of spreading food-borne diseases, and degrade the park landscape through overuse, trash and, at times, human waste.
Representatives of the religious groups testified that they have taken the city's free food-sanitation course and follow it in feeding the homeless and cleaning the area before and after the meals.
What they will not compromise on, however, is what they described as a God-directed mission to minister to the needs of homeless people where they live - outside on the parkway.
Their lawsuit contended that the ordinance violated the groups' First Amendment rights of free association and to freely practice religion.
In temporarily enjoining the ban, however, Yohn made no reference to constitutional issues. Instead, he focused on the lack of evidence there was any qualitative difference or advantage to feeding homeless people in front of City Hall compared to the parkway's green expanse.
Yohn said that in some ways - noise, traffic and obstacles to the disabled - City Hall was worse.
Yohn also said he heard very little evidence of any efforts to convince the homeless to make use of indoor dining facilities - an option many homeless people are reluctant to choose because of mental illness or other issues.
Coulter said Thursday night that King's Jubilee distributed food on the Parkway for about an hour. The group offered homemade chicken-noodle soup with kidney beans, spaghetti, sandwiches, hard-boiled eggs, oranges, peanuts, and baked goods.
He said the recipients were "thanking us that we pursued it in court, and that we won."
Contact Joseph A. Slobodzian at 215-854-2985, email@example.com, or @joeslobo on Twitter.