"I said absolutely not. It's one thing to forgive adultery; it's another thing to condone it," Jenny Sanford said in an interview, her first extended comments on the affair.

She said that when her husband, Gov. Mark Sanford, inexplicably disappeared last week, she hoped he was hiking on the Appalachian Trail. That he had dared to go to Argentina to see the other woman left her stunned.

"He was told in no uncertain terms not to see her," she said in a strong, steady voice. "I was hoping he was on the Appalachian Trail. . . . I was hoping he was doing some real soul-searching somewhere, and [was] devastated to find out it was Argentina. It's tragic."

The Sanfords had separated about two weeks ago. She said her husband told the family that he wanted some time away to work on writing a book and clear his head. The first lady said, "I had every hope he was not going to see her. You would think that a father who didn't have contact with his children, if he wanted those children, he would toe the line a little bit."

Mark Sanford returned Wednesday to end days of speculation on his whereabouts, publicly confess his cheating, and apologize.

Jenny Sanford said she discovered her husband's affair early this year after coming across a copy of a letter to the mistress. She felt "shocked and obviously deeply hurt. I didn't think he had it in him," she said. "It's hard to find out your husband is not who you thought he was."

She confronted her husband immediately, and he agreed to end the affair. She said yesterday that she wasn't sure he had done so. "I guess that's what we will have to see."

The governor declined to discuss details of the letter and how he handled it with his wife. "This goes into the personal zone," Sanford said yesterday. "I'd simply say that Jenny has been absolutely magnanimous and gracious as a wonderful Christian woman in this process."

Jenny Sanford cried at the end of the interview, and said the couple had been to counseling. "When I found out in January, we both indicated a willingness to continue working on the marriage, but there's not room for three people in a marriage," she said.

About an hour after Jenny Sanford's interview, her husband brushed aside any suggestion he might immediately resign, citing the Bible and the story of King David - who continued to lead after sleeping with another man's wife, Bathsheba, having the husband slain, then marrying the widow.

"What I find interesting is the story of David, and the way in which he fell mightily - fell in very, very significant ways - but then picked up the pieces and built from there," he told cabinet members in a session called to apologize to them in person and tell them the business of government must continue.

Some Republican leaders have called for Sanford to resign and some lawmakers and watchdog groups are pressing for investigations into whether he improperly used state money.

For Jenny Sanford, the focus is the couple's four sons. During her interview, she wept as she displayed the stellar report cards of her two eldest sons at their exclusive private school in Columbia.

On the coffee table was a collection of devotional books, including a book of commentary on the Bible's Book of Job, the story of a man whose faith God tests to the extreme.

"Parenting is the most important job there is, and what Mark has done has added a serious weight to that job," she said.