Buddhi

यः पठति लिखति पश्यति, परिपृच्छति पंडितान् उपाश्रयति।
तस्य दिवाकरकिरणैः नलिनी, दलं इव विस्तारिता बुद्धिः॥
yaḥ paṭhati likhati paśyati, paripṛcchati paṇḍitān upāśrayati |
tasya divākarakiraṇaiḥ nalinī‑dalaṃ iva vistāritā buddhiḥ ||

Whosoever reads, writes, observes, questions, and associates with scholars – his intellect expands like lotus‑petals unfolding in the rays of the sun.

yaḥ — he who
paṭhati — reads, studies
likhati — writes
paśyati — observes, examines
paripṛcchati — asks thoroughly, inquires
paṇḍitān — learned people, scholars
upāśrayati — approaches, seeks refuge in, associates with
tasya — his
divākara‑kiraṇaiḥ — by the rays of the sun (divākara = sun; kiraṇa = ray)
nalinī‑dalam iva — like the lotus‑petal
vistāritā — expanded, unfolded
buddhiḥ — intellect, understanding

This is lagna upadeśa explaining how the brain expands and the intellect grows. As an organ, the brain and the liver can grow even after suffering minor losses of mass. This is the strange power of the sunlight specifically mentioned in this śloka. It is the vāreśa that causes growth through upachaya if benefic graha.

The mūla mantra for this is the savitur gāyatrī.