Mahabharata 12.84.52

एवं सदा मन्त्रयितव्यमाहु;र्ये मन्त्रतत्त्वार्थविनिश्चयज्ञाःतस्मात्त्वमेवं प्रणयेः सदैव; मन्त्रं प्रजासंग्रहणे समर्थम्

evaṃ sadā mantrayitavyamāhu;rye mantratattvārthaviniścayajñāḥtasmāttvamevaṃ praṇayeḥ sadaiva; mantraṃ prajāsaṃgrahaṇe samartham

Our plain-language meaning of this verse is waiting for scholar review.