The PM also laid the foundation for an All India Institute of Medical Sciences (AIIMS).
Bonhomie was on display at an event in Darbhanga on Wednesday when Bihar Chief Minister Nitish Kumar bent down to touch the feet of Narendra Modi, only to be stopped by the Prime Minister, who shook his hands instead.
Having won 12 seats, Mr Kumar's Janata Dal United is the third largest partner in the National Democratic Alliance (fold) in terms of Lok Sabha constituencies. The party and Chandrababu Naidu's Telugu Desam Party played a key role in ensuring that Narendra Modi became Prime Minister for the third time after the BJP failed to secure a majority on its own for the first time in 10 years.
A video from the event shows Mr Kumar, who is 73, bending down and attempting to touch the feet of PM Modi, who is a year older than him, on a dais. The PM immediately gets up, holds the chief minister's arms and shakes his hands. Mr Kumar then sits next to the PM.
This is not the first time that Mr Kumar, who returned to the NDA fold after breaking away from the INDIA and Mahagathbandhan alliances earlier this year, has tried to touch the feet of PM Modi. He had done so during a meeting after the Lok Sabha results in June as well.
At the event, where he laid the foundation for an All India Institute of Medical Sciences (AIIMS) and inaugurated infrastructure projects worth Rs 12,100 crore, PM Modi praised the Bihar chief minister and said he had ensured the state emerged from "jungle raj".
"Nitish ji has set up a model of good governance ('sushasan'), pulling the state out of the era of jungle raj. No praise is too high for this achievement," the PM said.
"Bihar is witnessing a lot of development. The NDA government is committed to the welfare of the people. The previous government in Bihar didn't bother about health infrastructure. They made false promises, but the situation has improved since Nitish Kumar ji came to power," he added.