Bhagavad Gita 13.5
Seers have sung of it in various ways, in many hymns and sacred Vedic songs, weighty in thought and convincing in their arguments.
ऋषिभिर्बहुधा गीतं छन्दोभिर्विविधैः पृथक्।ब्रह्मसूत्रपदैश्चैव हेतुमद्भिर्विनिश्िचतैः॥ṛṣibhirbahudhā gītaṃ chandobhirvividhaiḥ pṛthak|brahmasūtrapadaiścaiva hetumadbhirviniśicataiḥ||
English translation (above): Shri Purohit Swami (1935), public domain. Sanskrit text via github.com/gita/gita (Unlicense).