"Work in such a manner, so you won't have to speak and your work will reflect," Kumar said, while addressing the Jharkhand JD(U)'s 'Karyakarta Sammelan' here.
"So, whenever I work I don't try to say much. If work happens then its impact will reflect," he said.
Recalling Jharkhand's bifurcation from Bihar in 2000 and how the then Samata Party (now JDU) had supported the creation, Mr Kumar said there was a mutual attachment between Bihar and the neighbouring state.
Talking about some of the efforts of his government to develop Bihar, he said distribution of bi-cycles among girls has changed the mindset of people, and girl students in class 9 have increased to over 15 lakh from 1.17 lakh.
"Other states came to see the cycle yozana and universities have also come to assess its impact...," Mr Kumar said.
The chief minister also said the liquor ban in Bihar has benefited numerous families, and now a technology was being developed through which anybody can call a team headed by the ADG/IG to inform about illegal liquor trade.