The RJD leader further said that ''it is not in their culture to say something to someone we respect'' but added he will write a book and explain everything.
In 2019, both the BJP and the JDU had contested on 17 seats each.
The INDIA alliance must draw some succour from the response to its rally in Patna on Sunday.
Lok Sabha Speaker Om Birla, Home Minister Amit Shah and Uttar Pradesh Chief Minister Yogi Adityanath also extended birthday wishes to Kumar.
While speaking during the Bihar floor test, Yadav asked how will JD(U) MLAs face public after Nitish Kumar's three oaths.
Though the NDA won majorly from Bihar during the Lok Sabha polls in Bihar in 2019, Nitish Kumar's withering away from the BJP could impact the new political formation.
Soon after the JD(U)-BJP split, a police official pasted "former" against the nameplate of deputy chief minister Tar Kishore Prasad.
Kumar, who was a long-time BJP ally before snapping ties in 2013 and again joining hands in 2017, said that there was a unanimous decision in the party meeting in the morning "to break off ties".
The RJD diktat to all senior party officials is not to make any public statement as its leadership works behind the scenes to turn the evolving situation in its favour.
Nitish Kumar will take oath as Bihar's chief minister for the 8th time today (Wednesday) afternoon at 2pm, after leaving BJP on Tuesday and forming new "Grand Alliance" with Tejashwi Yadav's Rashtriya Janata Dal (RJD) and other Opposition parties. Tejashwi Yadav will take oath as Deputy Chief Minister.
