Srimad-Bhagavatam: Canto 3 - Chapter 1 - Verse 21
मैत्रेय उवाचस उग्रधन्वन्नियदेवाबभाषेआसीच्च तूष्णीमरविन्दनाभम् ।धियोपगृह्णन् स्मितशोभितेनमुखेन चेतो लुलुभे देवहूत्या: ॥ २१ ॥
maitreya uvācasa ugra-dhanvann iyad evābabhāṣeāsīc ca tūṣṇīm aravinda-nābhamdhiyopagṛhṇan smita-śobhitenamukhena ceto lulubhe devahūtyāḥ
Śrī Maitreya said: O great warrior Vidura, the sage Kardama said this much only and then became silent, thinking of his worshipable Lord Viṣṇu, who has a lotus on His navel. As he silently smiled, his face captured the mind of Devahūti, who began to meditate upon the great sage.
It appears that Kardama Muni was fully absorbed in Kṛṣṇa consciousness because as soon as he became silent, he at once began to think of Lord Viṣṇu. That is the way of Kṛṣṇa consciousness. Pure devotees are so absorbed in thought of Kṛṣṇa that they have no other engagement; although they may seem to think or act otherwise, they are always thinking of Kṛṣṇa. The smile of such a Kṛṣṇa conscious person is so attractive that simply by smiling he wins so many admirers, disciples and followers.