Original text
ॐ आदित्याय विद्महे प्रभाकराय धीमहि । तन्नः सूर्यः प्रचोदयात् ॥
Transliteration
Om Adityaya Vidmahe Prabhakaraya Dhimahi Tannah Suryah Prachodayat
What this mantra means
The mantra addresses Surya as Aditya (son of Aditi) and Prabhakara (the one who brings forth light), before asking him — quite literally, since he's already the source of physical light — to illuminate the reciter's understanding, extending the sun's role as giver of light into a request for inner clarity.
Why sunrise matters for this mantra
Like most mantras dedicated to Surya, this one is traditionally chanted facing the rising sun, often alongside the offering of water (Arghya). Reciting it at sunrise is considered far more meaningful than reciting it at other times, since the mantra's entire premise — light dispelling darkness — mirrors what's happening outside as it's chanted.