Meaning
Supreme God Krishna spoke
When there is an emergence of light and knowledge in the body and its gates {and mind}, it indicates the ascendancy of the Noble Mode of Nature (SattvaGuna). (14:11)
Sanskrit
श्रीभगवान् उवाच
सर्वद्वारेषु देहेऽस्मिन्प्रकाश उपजायते ।
ज्ञानं यदा तदा विद्याद्विवृद्धं सत्त्वमित्युत॥
Word-by-word
सर्व-द्वारेषु देहे अस्मिन् प्रकाशः उप-जायते
ज्ञानम् यदा, तदा विद्यात् वि-वृद्धम् सत्त्वम् इति उत।
Commentary
The eyes, nose, tongue, ears, reproductive organs, etc., are the "gates" of the body. "Light" being produced in them means their turning Sāttvic, becoming purer in their interests. When the SattvaGuna is on the ascendency, ears do not want to listen to lousy gossip; eyes are not keen on watching the obscene and the evil; tongue loses interest in eating meat and fish, and reproductive organs lose interest in unethical sex.