Bhagavad Gita
11.12

दिवि सूर्यसहस्रस्य भवेद्युगपदुत्थिता । यदि भाः सदृशी सा स्याद्भासस्तस्य महात्मनः ॥

divi sūryasahasrasya bhavedyugapadutthitā | yadi bhāḥ sadṛśī sā syādbhāsastasya mahātmanaḥ ||

Translation

If the light of a thousand suns were to arise simultaneously in the sky — that might resemble the splendor of that great Being.

Interpretation

The most famous simile for the Vishvarupa: a thousand suns blazing simultaneously in the sky — and even that might only approximate the splendor of this great Being. This is the sun-times-a-thousand simile that has inspired poets, saints, and nuclear physicists alike. J. Robert Oppenheimer famously recalled this verse when he witnessed the first nuclear explosion. The splendor described is beyond anything visible in the ordinary universe — it requires the multiplication of the most powerful natural light to even gesture at the Divine's effulgence.