Krishna speaks of the unique guru-shishya-parampara or preceptor-disciple lineage. He says – I taught Vivasvan, the sun god, of the illustrious surya vamsha or solar dynasty. Vivasvan taught Manu, famous for his Manu Smrti or code of conduct. Manu gave it to Ikshvaku, the first king of the solar dynasty. Rama belonged to the Ikshvaku kula or family.
Arjuna is inspired but confused as he cannot understand how Krsna could have taught Vivasvan who lived many centuries before Him!