"Party members should work together to strengthen the party and should be careful with what they say in a public forum. Leaders should maintain good speech and conduct...they should have patience," said the new party president in a scarcely veiled word of caution to leaders like Mr Sinha and Ram Jethmalani, who had enthusiastically followed up Mr Sinha's surprise suggestion that Mr Modi be declared the BJP's candidate for PM in the 2014 general elections, with some Modi-praise of his own. Mr Jethmalani is known to be pro-Modi.
On Monday, Yashwant Sinha had said, " People and ordinary party workers have been demanding that the BJP should present Narendra Modi as the prime ministerial candidate. It is my opinion that if the BJP declares Mr Modi as its candidate for PM then it will benefit the party enormously in the elections."
He later told NDTV, "The Prime Minister's post in India does not go by qualification, it goes by popular appeal, and the point that I am making is that Narendra Modi today has the most popular appeal amongst the BJP leadership, and it will really be a game changer if he were to be projected."
The BJP's allies in the National Democratic Alliance have been vocal participants in the Modi debate that Mr Sinha began; they all agree that as the largest party, a BJP leader should front the NDA's 2014 campaign.
But the Janata Dal (United) quickly reminded the BJP that statements pitching for Mr Modi did not bode well for their 15-year-old partnership. JD(U) chief Sharad Yadav said, "Alliances are formed with great difficulty and Yashwant Sinha's statement is uncalled for in the context of alliances."
The JD(U) has repeatedly made it clear that the shadow of the 2002 Gujarat riots on Mr Modi's political career cancels him as the leader of the alliance.
The Shiv Sena said that it would prefer Leader of Opposition in the Lok Sabha Sushma Swaraj, also a top BJP leader, as the NDA's candidate for PM. Sukhbir Badal of the Akali Dal said Mr Modi was just the right man for the role.
With his statement, Mr Sinha, known to be a man of caliberated speech, has also made a clear move on behalf of a faction in the BJP that wants to keep the party's ideological mentor, the RSS, at bay while choosing the top leader.
Rajnath Singh has said the party leadership will decide a "bigger role" for Mr Modi in the run-up to the general elections. He spent two hours in closed-door discussions with Mr Modi on Sunday. Today, after addressing party workers and leaders at the BJP headquarters, Mr Singh met Ms Swaraj over lunch at her residence and reportedly discussed key party matters.