A New York rabbi testified yesterday that he paid $1,000 directly to Rep. Daniel J. Flood (D-Pa.) as part of a proposed "monthly payment plan" designed to secure the congressman's help in obtaining federal grants.

Rabbi Leib Pinter, wearing a full beard and a yarmulke for his appearance at Flood's trial, testified that he paid a total of $5,000 to $6,500 to Flood and Flood's administrative aide over a nine-month period in 1975 and 1976. His mission, Pinter said, was successfully completed when he received Department of Labor funds for the retraining of recent Soviet Jewish immigrants.

Pinter said he took most of the bribe money from a small cash fund raised through bazaars and teas sponsored by his organization, the Brooklyn-based B'nai Torah school and social welfare agency.

Pinter was the final prosecution witness in Flood's bribery, conspiracy and perjury trial in U.S. District Court here.

He was the sixth witness to testify to making direct payments to the 16-term Pennsylvania Democrat. A Pennsylvania home-builder, Robert Gennaro, also testified yesterday that he gave a $2,000 cash payoff directly to Flood in exchange for Flood's help in obtaining federal financing for a housing project.

The pattern described by the rabbi was essentially the same as it was for the housing developer, a foundation director, a banker, a lobbyist and others who have described payoffs.

Stephen B. Elko, Flood's administrative aide, would solicit the money in exchange for the favors, according to testimony. Either Elko or the payer himself would then present the bribe directly to Flood. Flood, often without any vocal acknowledgement, would accept the money and stuff it in his pocket.

After he began making payments, Pinter said he recalled Flood passing him in the hallway of a House office building, patting him on th back and saying: "Keep up the good work, Murphy.'"

Pinter said later in the trial that he did not know why Flood had called him Murphy.

Pinter, 35, is now serving a two-year sentence for bribery at the Metropolitan Correctional Center in Manhattan.

Flood's lawyers have denied that the congressman received any money at all in exchange for favors. Elko, who was the prosecution's chief witness, operated on his own, keeping the money for himself, defense lawyers maintain.

Except for Elko, no witness has testified that Flood actually acknowledged that the money he accepted was bribe money.Pinter, for example, testified that the money he paid was covered up as an honorarium for Flood's appearance at a December 1975 dinner Pinter organized in New York.

"Before the dinner I handed him [Flood] an envelope with a check [for $1,000] inside and said, "This is for the chairman,'" Pinter testified. The rabbi said there was no immediate response from Flood, who is chairman of the Appropriations subcommittee for the Departments of Labor and Health, Education and Welfare.

"Did that check represent an honorarium?" Pinter was asked by prosecutor Mark Tuohey.

"That was part of the nut," Pinter responded, noting that "nut" was the term used to describe the payoffs he had agreed to make to Flood and Elko.

The word "nut" was originally used by Elko, Pinter said, the man who first solicited bribes from him.

Pinter, said he had paid several small cash bribes to Elko in 1975 as the rabbi -- with help from Flood's office -- pursued Department of Labor money for a manpower training program at B'nai Torah, Pinter's Brooklyn-based operation.

However, in the fall of 1975, Pinter said, Elko asked that "a more suitable arrangement be worked out in which what he called a certain 'nut' -- a certain sum of money -- would be paid every year for the influence of Mr. Flood and his office."

The amount of $5,000 was agreed to. "I did not object to the figure," Pinter said, "but explained to him [Elko] that it could not be in a lump sum but rather in monthly payments."

Pinter said he had been taking the cash from the B'nai Torah safe, which contained small amounts derived from the teas and school bazaars. He couldn't continue to operate in this manner, he testified.

"I told Elko I was having trouble raising the cash and it would be better" if it came from the annual B'nai Torah fund-raising dinner. Pinter said he told Elko that Flood could be the "honored guest" and receive an honorarium "as far as the nut was concerned."

Pinter testified that the rest of the bribe money was disguised as campaign contributions to Flood from a variety of Pinter's friends.

The prosecution team, consisting of Tuohey, David Hinden and Karen Tandy, completed its case after eight full days of testimony.

The presentation has been vulnerable to attack because of the number of witnesses testifying under immunity, numerous contradictions in some testimony and the fact that the government has been unable to show how Flood used the money he allegedly received.

Its strength is based on the cumulative impact on a jury of witness after witness claiming to have paid bribes to Flood, even though the flow of the alleged bribe money cannot be completely traced.

The defense is expected to take about one week for its presentation.