Muhammed Hammad, a cousin of the bomber, said: "I never thought he would do such a thing. He didn't have the profile of suicide-bomber.
"I am shocked. It is difficult to believe it."
Samir Hammad, 21, a student at the al-Quds Open University, managed to evade Israel's ubiquitous army checkpoints on the West Bank and reached Tel Aviv where he carried out the bombing at a falafel sandwich stand on Monday.
The attack was claimed by the Islamic Jihad group, which did not sign to the Cairo-brokered truce in July last year. Hamas, which formed the new Palestinian cabinet last month, did.
Hammad came from Burqa, a village near the northern West Bank town of Jenin where electricity is available only at night.
His father Samih, a 50-year-old municipal worker in Jenin, could hardly make ends meet to feed his nine children.
Fatima Hammad, a distant relative, put the blame on Israel for Samir's actions.
Nine died in Monday's attack
"It is the Israeli oppression," said the mother of five.
"We don't like to see innocent people, including Jews, killed. But when they kill our children on a daily basis, our hearts are hardened and we try to make them drink from the same cup they have been forcing us to drink from all these years," she said, reflecting a sentiment shared by most in Burqa.
"They are killing our people on a daily basis, starving us, preventing us from work, and turning our daily life into an unbearable hell. So how are we supposed to behave under such circumstances? What are we supposed to do, kill ourselves?
"I think Israel is making each and every Palestinian a potential human bomber."
More to follow
In a video recorded before he set off for the attack, Hammad said he decided to carry out the bombing to avenge the "daily massacres Israel is perpetrating against our people".
He said 40 other martyr-bombers were following him.
Islamic Jihad blamed Israel for pushing the Palestinians to the edge of extermination.
"They are killing our people on a daily basis, starving us, preventing us from work, and turning our daily life into an unbearable hell. So how are we supposed to behave under such circumstances?
Relative of Samir Hammad
A spokesman for the group told Al Jazeera.net: "If we have to die, we won't die alone."
Soon after it was known that the bomber had come from Burqa, Israeli troops stormed the village and placed it under curfew.
The troops arrested Hammad's father and another man.
It was not immediately clear if the army would destroy Hammad's house - a routine punishment meted out to the families of Palestinian fighters who have killed Israelis.
Last year the Israeli High court ordered the practice suspended, saying that home demolition had very limited deterrence and was morally reprehensible.
In the meantime, the acting Israeli government was due to discuss "a set of retaliatory measures" against the Palestinians.
According to Israel's public radio, the government was considering one or all of the following measures: targeting the Hamas-led Palestinian government, cutting off the northern West Bank from the rest of the occupied territory and stepping up incursions and arrests.
About 10,000 Palestinians have been arrested since the beginning of the second intifada in September 2000, many of them without charge or trial.
Meanwhile, the Hamas-led government apparently retreated from earlier statements condoning the bombing.
Ahmed Yussuf, the government's spokesman, said that "the government was sorry for the loss of civilian lives," adding: "We hope that the cycle of bloodshed will come to an end."
"Human beings have a limited ability to endure stress and oppression. Ultimately, either they commit suicide or become suicidal bombers"
Hamas government spokesman
Yussuf said: "Continued Israeli killing of Palestinians, as well as mounting oppression and starvation, are pushing Palestinians to the edge.
"Human beings have a limited ability to endure stress and oppression. Ultimately, either they commit suicide or become suicidal bombers."
Mahmoud al-Zahar, the Palestinian foreign minister, who arrived in Riyadh on Monday night, refused to comment on the bombing.
Earlier statements by Sami Abu Zuhri, a Hamas spokesman, in which he called the bombing "an act of self-defence," were criticised by Israel and the United States.