Released Soviet Jewish dissident Anatoly Scharansky spent his first day in Israel today in virtual seclusion with his wife, Avital, and close friends, discussing his future as a new immigrant to the Jewish state, as special interest groups and political parties began jockeying to enlist his support.

Scharansky, who was given an Israeli passport and immigrant card upon his arrival last night, completed registration formalities and spent much of the day resting from his whirlwind journey from an East German jail to freedom in West Berlin and, later, a tumultuous reception at Tel Aviv's Ben Gurion Airport.

A source close to the family said that Scharansky was physically and emotionally exhausted, and that his wife, who had been under intense pressure in the days leading to her husband's release, was determined to remain secluded for at least a day or two.

The state-run Israeli radio reported tonight that in a brief interview -- the first he has given in nine years -- Scharansky said that during his time in detention he knew nothing of world events.

But he said that from time to time he could guess at changes in Soviet policy by the treatment accorded him by the KGB, the secret police.

In the interview, the radio reported, Scharansky said that he intended first to have some time to relax and then to devote his energies to working for the release of other Soviet Jews.

The radio said that in the interview, which was conducted in Hebrew, Scharansky, when asked if he had been instructed by the Soviets about what to say after his release, replied that throughout his captivity he had disobeyed the KGB's orders.

He said that when he was flown to East Germany, he was instructed by the KGB to walk from the aircraft in a straight line, but he said that in defiance he walked away in a zig-zag course.

In a television interview, Scharansky described how he clung to a Book of Psalms that Avital had sent to him. "Before my release they took all I had from me. I insisted that I take this book and lay down on the snow, refusing to take another step until I could have it. I said I would not leave Russia without it. They examined it and gave it to me."

The pocket-sized book, which he pulled from a pocket to show on television, was the only possession he was allowed to take with him from the Soviet Union, he said.

Looking pale but fit, Scharansky said an Israeli doctor who examined him was "shocked" when he described conditions during his captivity. Scharansky said he had spent 400 days in solitary confinement, including a 130-day stretch. "After 92 days I simply collapsed," he said.

He added that Avital "would write to me twice a week, and I would receive two letters a year from her. And that was in a good year. There also were years when I didn't receive a single letter."

Asked on state radio, about his first impressions here, he said, "All this is stronger than anything I saw anywhere in my dreams. You see, Avital wrote me once some years ago and said 'You can't even imagine what awaits you in Israel.' "

The couple was reported to be staying in the apartment of a friend in the religious Kiryat Moshe neighborhood of Jerusalem, shielded by friends who offered contradictory accounts of the Scharanskys' movements and plans.

But a senior government official in touch with the couple said Avital Scharansky, who for 12 years fought for her husband's release, had already begun to take up the cause for exit visas for his mother and brother, still in Moscow.

The official said she had appealed to President Reagan to intercede with Soviet authorities to allow Scharansky's mother, Ida Milgrom, and his brother, Leonid, to join them in Israel.

Scharansky telephoned his mother and brother early today, telling them of his release and last days in captivity.

An Israeli official who has talked with the Soviet human rights activist said that while Scharansky's future is uncertain, its initial stages at least would be dominated by working for the emigration of Soviet Jews through public appearances here and abroad.

Noting Scharansky's command of English and his worldwide reputation as leader of the Soviet Jewry emigration movement and cofounder of the Helsinki human rights movement, the official said, "I don't know what he will want to do ultimately, but it is obvious that he has a very major contribution to make in this field."

Meanwhile, special interest groups and political parties in Israel already have indicated an interest in enlisting Scharansky's support, as first evidenced by the appearance last night at the Ben Gurion international airport of Geula Cohen and other leaders of the right-wing Tehiya Party.

The party, with only three members in Israel's 120-seat parliament, has long urged that Israel proclaim sovereignty over the occupied West Bank and Gaza Strip.

Since she immigrated to Israel following her marriage to Scharansky in 1974, Avital Scharansky has become religiously orthodox under the influence of friends at the Mercaz Harav Yeshiva, a religious school, although her husband remains secular.

Some associates have suggested that there would be a struggle for the Scharanskys' support between secular, leftist parties involved in human rights activities and the rightist parties with strong orthodox influence who are active in the movement to increase settlements in the occupied territories.