प्रकृतेर्गुणसम्मूढाः सज्जन्ते गुणकर्मसु।तानकृत्स्नविदो मन्दान्कृत्स्नविन्न विचालयेत्॥
prakṛter guṇa-sammūḍhāḥ sajjante guṇa-karmasutān akṛtsna-vido mandān kṛtsna-vin na vicālayet
Word by word
The verse says
People fooled by the strands get attached to what the strands do. The one who sees the whole should not unsettle those who see only part of it.
In plain words
Verse 26's restraint, repeated, and now with a reason attached.
Akṛtsna-vid - those who know incompletely. Not fools. People with a partial view.
And na vicālayet - do not shake them. The one with the full picture should leave them steady.
Where you've felt this · in relationships
A friend is holding himself together with an account of why his marriage ended. You can see the account is not quite true. You can also see that it is currently holding the roof up, and there is nothing yet to put under it.
Going deeper
Twice in four verses, Krishna tells the person who understands not to disturb the person who does not. The repetition is deliberate and unusual.
The reason is in the previous verse. Krishna has just said the strands act among themselves and no self is doing anything. Handed to someone unprepared, that becomes nothing matters and nothing is mine to do, which is precisely Arjuna's position in Chapter 1 arriving by a new route.
So a truth that frees one person paralyses another, depending on what else is in place.
Mandān - the slow, the dull. It is the least kind word in the verse and it is worth not softening. The Gita does distinguish between people by capacity here.
But notice what follows from the distinction. It does not license contempt or correction. It licenses restraint. The one who sees more is given a duty of care toward the one who sees less, and the duty is to leave them their footing.