On the banks of the Blood River 139 years ago today, a small group of Boer farmers, trekking inland in ox-pulled covered wagons, repelled an attack by a large group of spear-carrying Zulu warriors.

Ever since then, the 2.3 million Africaans-speaking descendents of those mortrekkers have commemorated the [WORD ILLEGIBLE] as the pioneers promised God theywould. The religious holiday, knownas the Day of the Covenant, [WORD ILLEGIBLE] to symbolize the Afrikaners' predominancein this racially and culturally divided nation.

Gerrit Viljoen, rector of Rand [WORD ILLEGIBLE] University and head of the powerful Afrikaner secret society the [WORD ILLEGIBLE] told a gathering in Cape Town today that the battle of Blood River was "a victory for the timeless cultural values" of Afrikaner-ruled South Africa.

The day has a very different meaning to black South Africans. In the words of one religious leader, the Day of the Covenant is "a yearly reminder of a racial victory of one section of the population over another."

"Power is ours," answered the 1,500 blacks attending an interdenominational prayer meeting at Regina Mundi Catholic Church in the black township of Soweto.

"Today the Afrikaner nation is rejoicing its shome," said a black rector of the Dutch Reformed Church. "To kill is shameful . . . To be a robber is shameful . . . To be a racist is shameful and to want to reap from nothing and live on the sweat of others is shameful."

The prayer meeting was organized by the Black Priests' Solidarity Group and the Soweto Action Committee to remember jailed black leaders. There are estimated to be more than 700 detainees in South Africa, mostly blacks. The Soweto Action Committee was formed in the sprawling community of 1.2 million people to fill the leadership vacuum after the Oct. 19 detentions and bannings of black leaders and their organizations.

The prayers, speeches, songs and skits that lasts for three hours today preached black consciousness, black power, black beauty and the "liberation of South Africa."

"We don't mind if we are arrested, because we are looking forward to our freedom," said one speaker, while another warned, 'The people who beat us and throw tear gas at us, we shall get them with power in the near future."

Sister Mary Hosanna, whose family lives in Soweto and who has been a Catholic nun for 44 years, was there. About half the audience, like her, was middle-aged. The rest were teenagers or in their 20s. When the first clenched fists were raised in the power salute, Sister Mary Hosanna's arm was still. But by the end of the meeting her wrinkled black fist was up and clenched.

There was defiance at today's meeting, too. An unnamed student told the attentive audience, "We must fight and get our country back . . . We're not going to stop because of bullets . . . The white man is relaxed in your own country and is getting what you should be getting . . . Like the 'Minster of Injustice," Jimmy Kruger, who says he is going to have law and order at all costs, I say we will have our freedom at all costs."

Meanwhile, in white South Africa, Afrikaners trekked to their historical monuments. In some places, voortrekker camps were recreated, complete with costumes of the day. Audiences sat under the sun in lawn chairs, many holding their Bibles.

Although the Day of the Covenant is mainly religious, the main speakers at many of the ceremonies, were Cabinet members.

Minister of Interior and Information Connie Mulder said he thought it would be wrong to involve English-speaking people and others in the celebrations.

"Every nation must separate itself at certain times and I am not prepared to share this opportunity with others. They have their own," he said.

There was no reported violence on South Africa's 1977 Day of the Covenant, but the tense conflict that exists between two nationalisms, that of the Afrikaner and that of the blacks, was clear. Although they won the battle of Blood River. Afrikaners have not yet won the war.