Śatapatha Brāhmaṇa ("of a hundred paths") 11.8.3.11

11.8.3.11

bhāmeva candramasa ādatta tasmādetayoḥ sadṛśayoḥ satornatarāṃ candramā bhātyāttā hyasya bhā ā ha vai dviṣato bhrātṛvyasya bhāṃ datte ya evaṃ veda tadyadādatta tasmādādityaḥ

He took to himself the moon's shine; whence of these two (sun and moon), though being similar, the moon shines much less, for its shine has been taken from it; and, verily, he who knows this takes away the shine from his spiteful enemy. And inasmuch as he took these away (â-dâ), he (the sun) is called Âditya.