Today's warning came courtesy Vrishan Patel of the JD(U), a senior cabinet minister in the government headed by Nitish Kumar.
Tomorrow, BJP leaders from Bihar are scheduled to meet party president Rajnath Singh in Delhi where they will vent about the cutting attacks on the man who could be their party's prime ministerial candidate, Narendra Modi. They will also forecast how the BJP will perform if it decides to fight for Bihar's 40 Lok Sabha seats without its old ally.
In a televised speech on Sunday, Mr Kumar offered a lacerating assessment of Mr Modi, who is the chief minister of Gujarat. Mr Kumar did not name his counterpart from Gujarat, but it was so obvious who he was talking about that soon after, the BJP warned that no "unfounded inferences" should be drawn against the Gujarat Chief Minister.
Mr Modi is vying to be picked as his party's candidate for Prime Minister. But the JD(U) has said that the communal riots of Gujarat in 2002, when Mr Modi was serving his first term (he is now on round 4), make him unacceptable as the presumptive Prime Minister of the National Democratic Alliance, a political conglomerate of 11 parties which includes Mr Kumar's.
Yesterday, BJP leader and the Deputy Chief Minister of Bihar, Sushil Kumar Modi, took on his boss. He said that "It was unfortunate and objectionable the way JD(U) leaders attacked Narendra Modi."