Brihat Samhita
सुरचापपाटिततनुर्नृपतिविरोधप्रदः सहस्रांशुः । प्रावृट्काले सद्यः करोति विमलद्युतिर्वृष्टिम् ॥ ३-२७ ॥
If the solar disc should be crossed by the rainbow the princes of the land will be at war with one another. If in winter the disc be clear there will be immediate rain.
english translation
suracApapATitatanurnRpativirodhapradaH sahasrAMzuH । prAvRTkAle sadyaH karoti vimaladyutirvRSTim ॥ 3-27 ॥
hk transliteration by Sanscript