Rabbi Stuart Shiff, one of six New York rabbis employed by Aish HaTorah, a nonprofit Jewish-education organization, carries two pieces of equipment: a BlackBerry and a book of the Torah. Weekdays, he treks to businesses around the city on behalf of Aish’s Executive Learning Program—for a voluntary donation (average: ten thousand dollars), bosses who are too busy to go to shul can have a rabbi meet them at the office. “Studying the Torah took my mind off the stress,” Lisa Shalett, the C.E.O. of Sanford Bernstein, says in an Aish brochure.

“What this program does is it blows away all the excuses,” Shiff explained recently, in one of Aish’s conference rooms in midtown. “We have almost a postal carrier’s motto: nothing stops us.” It was 9:30 A.M. on the day before Hanukkah, and Shiff—who was wearing a black velvet yarmulke—had a meeting with Seth Horowitz, the former chief executive of Everlast, the boxing-supply company (which he had just sold for a reported hundred and sixty-eight million dollars). Horowitz, who is thirty-one, started studying with Shiff eighteen months ago. “I just needed to talk to someone,” he said, turning off his iPhone. “I’ve gained so much knowledge. This is the beauty of the program—the rabbi comes to your office, you discuss the Torah, and you talk about life.”

They had been reading Genesis 37, where Jacob arrives with his sons in Canaan. “ ‘Jacob settled in the land of his father’s sojournings,’ ” Shiff read. “Now, there’s an interesting extrapolation in the rabbinic commentary. It says vayeshev—that Jacob wanted to dwell. The extrapolation is that he wanted to have a life of ease. He didn’t want to have pressure or issues.” Then disaster happens: Joseph, Jacob’s favorite son, is sold as a slave into Egypt. “It’s a very strange thing here,” Shiff said. “All Jacob wanted was some peace and quiet. What’s so wrong with that?”

Horowitz leaned back in a swivel chair. “It’s kind of the opposite of what we’re here for? Free will? Our opportunity to choose between good and bad?”

Shiff’s exegesis abounded with business-world metaphors: in prison in Egypt, Joseph mistakenly puts “all his trust in his network,” but he later rises to become “like the vice-president” of a company. Shiff had an appointment at eleven, at Bear Stearns. He arrived in a cluttered corner office where an executive in pinstripes was yelling into a telephone. A secretary sat nearby. She explained that although she was not Jewish, she enjoyed listening in on Shiff’s weekly visits. “I love everything about the Jewish faith,” she said. “I think it has a lot of wisdom.” The executive hung up the phone. “Basically, I’m a quasi disbeliever,” he explained. “I like talking to the rabbi, because I challenge him on a lot of the stuff. I like to ask my questions, which are mostly about the rigidity of religious beliefs. I’m probably his worst patient, if you want to call me a patient.”

“Maybe we can talk a little bit about Hanukkah,” Shiff said.

“O.K.,” the executive said. “Seven candles?”

“Eight! We light eight candles to commemorate a miracle. What’s the miracle we’recommemorating?”

“I don’t know.”

“They found oil in a temple that was desecrated by the Syrian-Greek army,” Shiff began. He got as far as the eight days, and the executive interrupted. “Where did they get the idea in the first place? That’s my question—who wrote the book?”

“The Maccabees,” Shiff said. “It’s history.”

“Yeah,” the executive said. “History I can buy.” They discussed the Jewish calendar (it’s both lunar and solar), and got around to Hanukkah presents. “I didn’t have them when I grew up,” the executive said. “I don’t think you should have them.”

Shiff said, “It’s probably better that way.”

When the session was over, Shiff got on the No. 6 train and headed uptown, to meet his twelve-thirty—a neuroscientist at Mount Sinai who was looking to the Kabbalah to illuminate his findings on postpartum depression. (At his last session, the client had become fascinated by the decree, in Genesis, that “in sorrow thou shalt bear forth children.”) “We go everywhere,” Shiff said on the train. “We go to J. P. Morgan, Bear, Bloomberg, Goldman—and everybody is so different. It’s not about conforming to anything. That last guy, I think sometimes he thinks he’s not living up to my expectations of him. But I don’t have any expectations. My whole job is helping him to stay connected. We like questions.”