IN the essay, Ofer Shelah, a veteran commentator, said that he had followed Mr. Mofaz for nearly 35 years. “Mofaz is a focused man in a way that is almost superhuman,” he wrote, adding that the new opposition leader had learned that “there is always an opening, if not through the door then through the window — a lesson he first learned when he failed three times to be accepted to the army’s officer training course.”

Mr. Mofaz plans to turn his modest background and unassuming assiduousness into assets at a time when many feel alienated from leaders like Defense Minister Ehud Barak, who recently sold an apartment for millions of dollars. Mr. Mofaz said that when social protests over high prices and indifferent government resume, as expected, this summer, he will be part of them because he understands the protesters.

“I have four children, two of them married, and three grandchildren,” he said. “My kids are among the young couples that can’t make ends meet. They work hard and can’t finish the month. In Israel of 2012, only part of the population enjoys the fruit of the country’s economic growth. The rich get richer and the poor poorer.”

Mr. Mofaz was born in Tehran and moved with his family to Israel at the age of 9, settling in the southern port of Eilat. His father had been a school principal in Iran, but his attempt to open a small factory in Eilat in the 1950s failed, and he was forced to seek work as a menial laborer. The family lived in one and a half rooms, two children to a bed, and there were days when the refrigerator was empty. At age 10, Mr. Mofaz worked in construction.

When he was 14, his father sent him to an agricultural boarding school in Nahalal, in the Jezreel Valley in northern Israel, a full day’s travel from home.

In an interview in 2009 with the newspaper Haaretz, Mr. Mofaz described what it was like for him there among the European elite.

“You’re in class with children from Nahalal who are Israelis with real roots in the country, children of the valley nobility,” he said. “These princes who live in the big houses on the big farms of Nahalal, and where do you come from? From nowhere, from Tehran, from Eilat, from a tiny apartment in a housing project.”