We have heard from wise men that vidya and avidya give different results.
In this sloka, the Rishi of Upanishad quotes the teaching of wise men to confirm that result of karma (avidya) and upasana ( vidya) are different. Rishi is ascertaining this to indicate that previous sloka is not just based on his understanding, but opinion of other Realized Masters as well.
Those who follow blindly rituals go through repeated cycle of births and deaths while those who pursue vidya ( upasana of minor deities) go to the world of those deities. On exhaustion of karma phala they are again born in human or animal domain.
Sanatana Dharma doesnot rely on mental speculations, intellectual postulates but teaching of Realized Masters for Truth.
इति शुश्रुम धीराणां ये नस्तद्विचचक्षिरे ॥ १० ॥
iti śuśruma dhīrāṇāṃ ye nastadvicacakṣire || 10 ||