Meaning
Supreme God Krishna spoke
One who stays neutral {like a witness}, is not disturbed by {the interplay of} Modes of Nature, and understands that the role of the Modes is to remain engaged in their natural interplay, {and having understood this} remains calm and collected and never budges from that position; (14:23)
Sanskrit
श्रीभगवान् उवाच
उदासीनवदासीनो गुणैर्यो न विचाल्यते ।
गुणा वर्तन्त इत्येवं योऽवतिष्ठति नेङ्गते॥
Word-by-word
उद्-आसीन-वत् आसीनः, गुणैः यः न वि-चाल्यते,
गुणाः वर्तन्ते इति एव यः अव-तिष्ठति, न इङ्गते;