Brihat Samhita
सूर्यस्य विविधवर्णाः पवनेन विघट्टिताः कराः साभ्रे । वियति धनुःसंस्थाना ये दृश्यन्ते तदिन्द्रधनुः ॥ ३५-०१ ॥
The many coloured rays of the Sun falling upon the clouds and being broken by the winds take the shape of the rainbow in the sky,
english translation
sUryasya vividhavarNAH pavanena vighaTTitAH karAH sAbhre । viyati dhanuHsaMsthAnA ye dRzyante tadindradhanuH ॥ 35-01 ॥
hk transliteration by Sanscript