Addressing a big rally in which Lok Janshakti Party chief Paswan and his son Chirag appeared for the first time with him after the two parties stitched an alliance last week, he said the country's polity was now divided into two camps.
"One headed by us is looking for a solution to country's problems while the other is searching for a solution to stop Modi," the Bharatiya Janata Party’s prime ministerial candidate said.
Praising Paswan, Modi said he had remained courteous to him in personal meetings and did not shy away from being photographed with him despite their ideological differences, an apparent dig at Kumar.
Without naming Kumar he said, the Bihar CM was a "hypocrite" who met him with affection in a closed room and ate together but feared shaking hands in public.
“People pardon your mistakes but not hypocrisy,” he said.
Paswan, who had quit the National Democratic Alliance government at the Centre in 2002 after the Gujarat riots blaming Modi, on Monday said there is a wave in favour of Modi which will take him to the seat of power.
"Modi was born in a poor family who says he has been a victim of political untouchability... He is going to wear a crown of thorns. I hope no community will say a year later that Modi is not their leader," he said, apparently referring to Muslims' unease towards Modi.
The Gujarat chief minister touched on the terror blasts in his Patna rally in October last year on the day of his rally to hit out at Kumar.
"The border (Bihar's) with Nepal is a cause for concern. Bihar has become a haven for terrorists due to vote bank politics of the government. It has not adopted tough policies against them to appease some people," he said.
You may not like Modi or BJP but those who died in the blasts were also from Bihar, he said. "Those indulging in the politics of vote bank do not understand this ideology... sooner we get rid of such people, the better it is."
Modi also alleged that the Third Front was only aimed at promoting the interest of the Congress and cannot do any good for the country.
"The Third Front is actually aimed at promoting the interest of the Congress," he said addressing party rally while launching an attack on Kumar.
"Did you hear about Third Front a year or six months ago? ... It has come (into being) on the eve of elections... It can spoil the elections but can do no good for the country," the BJP prime ministerial candidate said.
Coming down heavily on the Congress and other parties, he said while for the BJP secularism meant promoting the interests of all castes and communities and ushering the country on the path of development but for the others it has a "narrow meaning of stopping Narendra Modi from coming to power".
Tearing into Kumar's development claims, he quoted statistics stating that only 23 per cent households in the state have toilets and only 16 per cent have electricity.
Paswan to share dais with Modi at Muzaffarpur rally
No breakthrough in seat-sharing for Congress in Bihar
Court dismisses defamation case against Modi, Rajnath
Two regional parties merge with Trinamool in Jharkhand
Cong led JD-U up the 'garden path' on special status: Jaitley