Only eight Lib Dems were elected, down from 57 in the previous Parliament.
Mr Farron said he intended to visit Israel and the West Bank for the first time this year.
He said he would not criticise the party’s failure to dismiss Mr Ward, after he refused to apologise for saying he would fire a rocket into Israel if he lived in Gaza.
Asked if he was disappointed to see Mr Ward lose his seat, Mr Farron said: “Given the importance of the liberal voice, I was saddened to lose any of my colleagues and David Ward was a good constituency MP.
“What he said was intolerable and inexcusable. It is one thing to feel deeply for the Palestinians, it is another to support terrorists.”
He added that party had been "pretty harsh" in removing the whip from Mr Ward but that it was the right thing to have done.
In 2013, Mr Ward had his party whip withdrawn over comments he made about Israel.
The former MP was suspended from the party in 2013 after he wrote on his website that he was: "Saddened that the Jews, who suffered unbelievable levels of persecution during the Holocaust, could within a few years of liberation from the death camps, be inflicting atrocities on Palestinians in the new State of Israel and continue to do so on a daily basis in the West Bank and Gaza."
Mr Farron said he would have “no truck” with antisemitism if he were to be elected leader.
Reflecting on the Israel-Gaza war last summer, the 44-year-old said: “It was disproportionate - I thought the Israel government did behave in ways that were counterproductive to her own interests.
“Clearly, there was blame on both sides; both sides are victims and both sides are aggressors.
“My advice to the Israeli government then – and my view now – is I want to defend Israel’s right to security in her borders. Sometimes, Israel makes it hard for us.
“I am a friend of Israel. Your best friends tell you when your breath smells.”
Mr Farron, who is opposed to the boycott, divestment and sanctions movement, added: “One of the things I want us to do is promote the party’s support of Israel as a state and people.
“The answer to the crisis is a two state solution – that has got to be our focus.”
Mr Farron said he would fight the proposed removal of the Human Rights Act under the Tory government – adding that its repeal would foster radicalism within the Muslim community.
He said: “[The Conservatives] are trying to look tough, but it is leading to long-term division.
“I would deal with [radical Islam] by not isolating them, but by reaching out to them.
“I am not saying we should not be concerned with [Islamic State] returners, but we should be talking to the community. Community leaders do not want to be associated with radical Muslims.”
Mr Farron said he would like to see Mr Clegg take on a high-profile role in the party, “but it is up to him”. He said the “disappointing result – the drop in support was pretty nationwide – we had an election that was based on nationalism and fear.
“It is more important than ever to have a liberal voice that is not based on negativity and fear of ‘the other’.
“What that election told me was that we need a liberal voice in British politics more than anything else.”
Mr Farron’s candidacy is backed by senior British Jews in the party, including Lord Palmer who said: “I’m excited at the prospect of Tim as Leader. Tim is a man of great enthusiasm and commitment and I am convinced that under his inspiring leadership Liberal Democracy will go from strength to strength”.
Outgoing Board of Deputies treasurer Laurence Brass, who once was a Lib Dem parliamentary candidate, and Ben Rich, the party’s former deputy director of policy, are also backing Mr Farron.
Mr Rich said: “As a person of faith he ‘gets’ the Jewish community and I am confident will listen to our concerns.”
Mr Farron said that he understood the importance of religious practices as a Christian – adding that he would protect brit milah and shechita. “I am very passionate about tolerance for religious minorities – keeping up with rituals is part of religious observance,” he said.
Mr Farron visited Auschwitz five years ago, adding that the concentration camp “had a deep impact, the sheer scale of suffering. We have to keep [the memory of the Holocaust] alive”.
Mr Lamb, the MP for North Norfolk, did not respond to requests for interview.
Read our full Election 2015 coverage here
