ऋषिभिर्बहुधा गीतं छन्दोभिर्विविधैः पृथक्।
ब्रह्मसूत्रपदैश्चैव हेतुमद्भिर्विनिश्िचतैः।।13.5।।
13.5 Sages have sung in many ways, in various distinctive chants and also in the suggestive words indicative of the Absolute, full of reasoning and decisive.
13.5 Gitam, It has been sung of, spoken of; bahudha, in various ways; rsibhih, by the Rsis, by Vasistha and others; sung prthak, separately; vividhaih, by the different kinds of; chandobhih, Vedic texts-chandas mean the Rg-veda etc; by them; ca, and; besides, hetumadbhih, by the rational; and viniscitaih, by the convincing, i.e. by those which are productive of certain knowledge-not by those which are in an ambiguous form; brahma-sutra-padaih eva, sentences themselves which are indicative of and lead to Brahman. Brahma-sutras are the sentences indicative of Brahman. They are called padani since Brahman is reached, known, through them. By them indeed has been sung the true nature of the field and the Knower of the field (-this is understood). The Self is verily known through such sentences as, The Self alone is to be meditated upon (Br. 1.4.7), which are indicative of and lead to Brahman. To Arjuna who had become interested as a result of the eulogy, the Lord says:
Rishibhirbahudhaa geetam cchandobhirvividhaih prithak; Brahmasootrapadaishchaiva hetumadbhirvinishchitaih.
ṛiṣhibhiḥ—by great sages; bahudhā—in manifold ways; gītam—sung; chhandobhiḥ—in Vedic hymns; vividhaiḥ—various; pṛithak—variously; brahma-sūtra—the Brahma Sūtra; padaiḥ—by the hymns; cha—and; eva—especially; hetu-madbhiḥ—with logic; viniśhchitaiḥ—conclusive evidence