President Reagan asked television journalist Jeremy Levin to refrain from disclosing publicly any details about his ordeal as a hostage in Lebanon that "even inadvertently" might endanger four other Americans presumed kidnaped by the same terrorists. "I can't tell you how gratified Nancy and I were to learn of your escape," Reagan said in a telephone conversation with Levin broadcast on the Cable News Network. "Your abduction and that of our other Americans has weighed heavily on us for nearly a year. And not . . . a day has gone by that you weren't in our prayers."