A person who has made up their mind moves like an arrow — one direction, one target, full force. Their intellect is unified. But a person who has not decided keeps branching into endless possibilities — should I do this, should I try that, maybe the other thing — and their energy scatters like water spilled on sand.
Krishna draws a vivid contrast here. The resolved mind is 'eka' — one. The unresolved mind is 'bahushakha' — many-branched — and 'ananta' — endless. One is a river flowing in a single channel, deep and powerful. The other is a delta splitting into a hundred shallow streams, none of which reaches the sea with any force.
This applies far beyond the battlefield. A student who commits to one subject and studies it deeply learns more than one who samples ten subjects and commits to none. A gardener who tends one patch well grows more than one who scatters seeds everywhere and tends nothing. Resolution is not stubbornness — it is the disciplined choice to go deep rather than wide.