A tense cease-fire in the Christian city of Zahle, reportedly arranged after a direct Lebanese plea to Syrian President Hafez Assad, and a slowed pace in the shelling in Beirut tonight brought at least a temporary lull to the most serious fighting in Lebanon in three years.

The three days of fighting here and in Zahle, largely between right-wing Lebanese Christian militias and the all-Syrian Arab Deterrent Force brought here five years ago in a peace-keeping role, have left 94 persons dead and more than 300 wounded, according to the most recent estimates.

Meanwhile, seaborne Israeli commandos stormed ashire in southern Lebanon today and killed at least two Palestinian guerrillas in a three-hour battle. Israeli military sources said the objective was near Ras Saidad, where a strike last May 7 killed at least six guerrillas.

The attack, Israel's third strike against suspected guerrilla positions in four days, is expected to complicate efforts by the Lebanese government to find a political solution to the fighting.

The Syrians are said to be determined to secure Zahle, a strategically located town 50 miles east of Beirut in the Bekaa Valley, as a link through the valley to beleaguered southern Lebanon.

By tonight, the thunder of heavy artillery, rocket and mortar duels had died down, though there were light exchanges of machine-gun and sniper fire, as the cease-fire took hold in Zahle.

The state-supervised Lebanese television and military sources at the Christian Phalange Party confirmed reports of the cease-fire. A military Phalangist source disclosed that the cease-fire was pledged by Assad to Lebanese Public Works Minister Elias Hrawi, who was helicoptered in a military plane into the Syrian capital of Damascus as the Lebanese Cabinet was meeting in day-long but inconclusive sessions.

A midday lull in the fighting allowed International Red Cross employes to enter the town briefly with medical and food supplies. Residents of the town of 160,000 today endured a third day of intensive shelling by Syrian forces that are blockading its approaches and entrenched in the surrounding hills.

A Zahle resident contacted in late afternoon said she and her husband still did not dare leave their home, and that their children were still with other students, teachers and elderly people in the basement of a nearby school. Residents were still doing without water, electricity, fresh food and proper sanitation in most sections of the city, she added.

In Beirut, tension along the traditionally explosive dividing line between the capital's mainly Moslem western sector and the predominantly Christian east persisted today, but not with the same fierceness as yesterday's battles.

The independent newspaper An Nahar today reported that confrontations along the demarcating Green Line had started between elements of the Palestine Liberation Army [the Palestinian contingent of the Syrian Army] positioned west of the city's commercial district and Lebanese Army soldiers manning checkpoints on the other side.

Despite conflicting reports yesterday of clashes between Christian militiamen and the Palestinian soldiers, backed by their Moslem-leftist allies, the official spokesman of the Lebanese Christian militias today denied his group's involvement in combat across the Green Line.

"We never responded to the PLA because their offensive is a Syrian trap. And if the Syrians think they can distract us or pressure us on the issue of Zahle, let it be known that this is out of the question," the spokesman said.

The Defense Ministry announced late last night that one Lebanese Army soldier was killed and 13 others wounded in the clash.

A gloomy sense of anxiety and uncertainty reigned over the capital today, as shoppers lined up at bakeries and business came to a standstill, bringing back memories of the 1975-76 civil war and the grave Syrian-Christian fighting of 1978.

In a late-evening newscast the Phalangist radio reported clashes between Lebanese Army troops and Syrian Army units in Hadath, a southeastern suburb.

Although the cease-fire seemed to be holding three hours after its announcement, emotions on all sides remained high.

The Damascus-based correspondent of Radio Monte Carlo, quoting high-ranking Syrian government and military sources, warned that "the [Arab Deterrent Force] will keep up their efforts until the Phalangists are routed out" of Zahle.

Bashir Gemayel, the most powerful leader of the Christian camp, said on the same program: "Let everyone understand, and understand very well. We have had enough and we will take no more."