18:67
इदं ते नातपस्काय नाभक्ताय कदाचन ।
न चाशुश्रूषवे वाच्यं न च मां योऽभ्यसूयति ॥१८- ६७॥
idaM te naatapaskaaya naabhaktaaya kadaachana ।
na chaashushrooShawe waachyaM na cha maaM yo'bhyasooyati ॥१८- ६७॥
Source: Automatic ITRANS Transliteration
This is never to be told to those who are inaustere, undevoted,
Or irreverent, and not to any who resent me.
Source: Milind S. Pandit
This (knowledge) should never be spoken by you to one who is devoid of austerity, who is without devotion, who does not desire to listen, or who speaks ill of Me.
This confidential knowledge may not be explained to those who are not austere, or devoted, or engaged in devotional service, nor to one who is envious of Me.
Source: Bhagavad Gita As It Is