His Iran-contra testimony was a painful chapter in the education of Elliott Abrams, and for the congressional committees investigating that affair it provided difficult knowledge of another sort.

Abrams had learned, he testified on his final day before the select committees yesterday, that "there is such a thing as being too clever." As evidence of the truth of his remark, his own reputation for veracity is under attack and his job at risk.

Members of the Iran-contra committees were learning from Abrams' testimony that despite all that has happened since last November, they still have cause to worry about the truthfulness of the administration when officials brief House and Senate committees. Many members expressed wonder about whether the sort of secret policymaking that produced the Iran-contra affair has in fact been abandoned.

Abrams' assertion yesterday that he intends to stay on as assistant secretary of state for inter-American affairs, after intensive questioning about his past misleading statements to Congress, produced the sharpest exchange of the hearings so far and exposed a deep strain of growing anger between Capitol Hill and the White House.

"I've been very troubled with the job that you did," Rep. Jack Brooks (D-Tex.) bluntly told Abrams, "because you would have us believe that you just had no idea about private fund-raising, about solicitation to foreign governments for a few million dollars, you had no idea about how the contras were operating or where they were getting their supplies, you had no idea about a large number of people who were commuting almost daily between the United States

and your area of surveillance. And yet, these

missions went on for months while you were in office."

Brooks, his voice rising as he spoke with obvious anger, told Abrams:

"You are the only man I ever saw that takes more pride in not knowing anything than anybody I ever saw . . . . And I can only conclude after this that you're either extremely incompetent or that you are still, as I say, deceiving us with semantics -- or, three, maybe the administration has intentionally kept you in the dark on all these matters so then you could come down and blatantly mislead us -- the secretary of state and the American people -- on all of these issues that we've been discussing."

When Abrams objected to Brooks' statement as "erroneous," the congressman snapped:

"I wouldn't think that you would agree with one bit of it, because you've been very patiently telling us . . . you weren't authorized to tell the truth. That's the wildest story I ever heard."

Sen. Sam Nunn (D-Ga.) succinctly expressed a concern that seemed widely shared by members of both parties when his turn came to interrogate Abrams.

"You're going to remain, according to your testimony, in your present position," Nunn said. "That position, as you've already described it, is a key position as spokesman and also policymaker and {involves} a considerable amount of testimony before key committees, including the {Senate} intelligence committee. Now the next time you appear for an important matter before the intelligence commitee, my question is, how should we question you? . . .

"Over and over again you've said that you weren't informed on this, that and the other, or you were misled," Nunn said.

"Now, how are we supposed to know that you are informed when you appear before the committee? . . . How are we supposed to know whether you are authorized to tell the truth? . . . In other words, before we ask you substantive questions each time you appear, do we need to precede that by asking you if you're authorized on this subject to tell the truth, the whole truth and nothing but the truth? Is that the way we begin our questioning of Elliott Abrams?"

Nunn asked the broader question that increasingly troubles members of both parties on the Iran-contra committees.

"Forget about Congress," he said. "Forget about the intelligence {committee} meeting. How does the executive branch operate when so many people are misleading so many other people, and particularly with you in a key position, and you were being misled over and over and over again, according to your testimony?"

Abrams replied:

"You can't operate that way, and I think that we in the executive branch and you in the Congress know that the way in which that was being operated in the executive branch was a disaster and the thing just fell apart. It was being operated by the NSC {National Security Council}, keeping the Department of State in the dark, and that, that is a formula for disaster."

In the education of Elliott Abrams, that awareness might have come too late. Abrams left the stand yesterday after hearing several committee members say they do not think he will survive as assistant secretary of state.