“We support the intifada, but we are against the use of arms in the intifada,” he told some 5,000 people gathered at the Al-Najah University.
He told an Israeli newspaper he is looking forward to peaceful times.
“If I win the elections, that will be an excellent opportunity for peace,” he said, reiterating his controversial condemnation of rocket attacks on Israeli targets by Gaza militants.
During his Nablus appearance, he underlined his commitment to an estimated 8,000 Palestinians imprisoned by Israeli authorities.
“We will not forget our prisoners,” he said to applause.
This comes as the Israeli Supreme Court rejected an appeal to allow Palestinians held in Israeli jails to vote in Sunday’s election to elect a successor to Yasser Arafat, who died two months ago.
Palestinian prisoner affairs minister Hisham Abdelrazzeq, who had lodged the appeal, described the decision as “illegal”.
Both Mr Abbas and his closest rival in the latest opinion polls, Mustafa Barghuti, will close the electoral campaign on Friday with a tour of the Jerusalem area.
Palestinian group Hamas, which has not fielded a candidate in Sunday’s election, has called on supporters to boycott the vote and lambasted Mr Abbas for criticising its rocket attacks, accusing the co-founder of Fatah of “stabbing the resistance in the back”.
Israeli activists have vowed to hamper the vote by clogging up post offices in east Jerusalem, which will be used as polling stations, however this would only affect a small number of Palestinians, most of who are expected to vote within the West Bank boundaries.
Meanwhile, Jewish West Bank settlers have challenged the authority of Israeli Prime Minister Ariel Sharon as they continue to rail against the planned withdrawal that would see their homes disamantled.
More than 30 reserve officers living there wrote a petition to their commander describing the withdrawal as “patently illegal.”
They now face being sacked from the military over their appeal.