Natyashastra
देवतासुरमानन्द्य यस्माँल्लोकश्च नन्दति । तस्मादयं प्रयोगस्तु नान्दीनामा भविष्यति ॥ २२॥
The performance, which delights both gods and demons and brings joy to the world, will henceforth be called Nāndī (Benediction).
english translation
devatAsuramAnandya yasmA~llokazca nandati । tasmAdayaM prayogastu nAndInAmA bhaviSyati ॥ 22॥
hk transliteration by Sanscript