Matsyapurana 124.4

124.4

trīṃllokānprati sāmānyāt sūryo yātyavilambataḥ
acirāttu prakāśena avanāttu raviḥ smṛtaḥ //

The sun and the moon shed their lights on the circumference of the Earth. The learned believe the heaven to have a similar circumference. The sun ordinarily lits up the three worlds in a moment. He is called Ravi, for giving instantaneous (र=at once) light and thereby protecting (वि=protect) the creation.—3-4.