The Rev. Jesse L. Jackson, preaching from the pulpit at a Memorial Church service marking the birthday of the Rev. Martin Luther King Jr. yesterday delivered a blistering attack on Harvard for continuing to hold investments tied to South Africa.

"The Harvard-South Africa kinship is a marriage born in hell." Jackson told a standing-room-only audience of about 900.

"The Harvard-South Africa kinship makes crimson become red," he continued. "It symbolizes collusion with those who spill the blood of the innocent..."

"Every investment is a prison bar holding Nelson Mandela," said Jackson, refering to the leader of the African National Congress imprisoned in South Africa since 1962.

Jackson also called for a March 11 "people's pilgrimage of conscience" to Washington. D.C. to "tell out Senators and Congressmen about the consequences of poverty and hunger."

"Were it not for his vision and his courage, it is not likely that I would stand here today," Jackson said of King, "much less as someone who ran for the highest office in the land."

"Even today, 17 years after his death doors that once were closed and locked are still being opened because of the legacy of Dr. King," Jackson, clad in the minister's traditional long black robe, added.

In the heavily political 50 minute speech reminiscent of his speeches during the campaign for the Democrats presidential nomination. Jackson strongly criticized the Reagan administration for raising defense spending while cutting spending on domestic feeding programs.

"Dr. King would remind its that now is the time for leadership. It is new that we decide whether the B-1 bomber is more important than a child's school lunch. Now is the time to decide whether the MX missile gives us more security than the nutrition programs which feed our families and the elderly."

He said that eliminating two aircraft carriers from the Defense Department budget would pay for all the administration's cuts in nutrition programs.

Jackson called for the elimination of hunger in America as a "birthday present fit for a King" and said "each of us can give Dr. King our own personal gift--a gift of our time, our hearts, our convictions and our efforts to continue the work begun by him."

The Rev. Peter J. Gomes, the minister of Memorial Church said the heavily political content of the speech came as no surprise.

"I certainly assumed he was going to give the inaugural address the country didn't let him make," said Gomes. "This was as good a platform as any to annouce that he's still in business, and he did that with passion and conviction."

"I'd say his audience was ready to inaugurate him on the spot," Gomes added.

King, who was slain in Memphis, Tennessee on April 4, 1968, would have been 56 years old yesterday. In the 1960s Jackson rose quickly to become one of King's top lieutenants in the civil rights movement. Jackson was in Memphis with King when he was shot. The flamboyant Jackson claims he was the last person to speak to King before he died, though others who were in Memphis have disputed this.