Rig-Veda. 6. 61 is the Sukta which is devoted to Sarasvati. In this sukta she is praised as Goddess and adored as river. The sanskrit mantras and H.H.Wilson translation is as follows. The Translation of H.H. Wilson is based on commentary of Sayana.
इयं शुष्मेभिर्बिसखाइवारुजत्सानु गिरीणां तविषेभिरूर्मिभिः ।
पारावतघ्नीमवसे सुवृक्तिभिः सरस्वतीमा विवासेम धीतिभिः ॥ RV.6.61.2 ॥
सरस्वति देवनिदो नि बर्हय प्रजां विश्वस्य बृसयस्य मायिनः ।
क्षितिभ्योऽवनीरविन्दो विषमेभ्यो अस्रवो वाजिनीवति ॥ R.V. 6.61.3 ॥
2 With impetuous and mighty waves , she breaks down precipices of the
mountains , like a digger for the lotus fibres. We adore for our
protection , with praises and with sacred rites , Saraswati the
underminer of both the banks.
3 Destroy , Saraswati , the
rivilers of the gods , the offspring of universal deluder , Vrisaya :
giver of sustenance , thou hast acquired for men the land (Seized by
asuras) , and hast showered water upon them
In the Comment section of this sukta H.H. wilson is also providing the commentary based on Sayana Bhashya . So according to Sayana this Brasaya (बर्सय) is another name of Tvashtri the father of Vritrasura. below is the excerpt from the commentary.
Vrisaya is a name of Tvashtri , whose son was Vritra : in Sayana's
introduction to the Black , or Taitariya Yajush ,a curious legend is
So it is clear that Brasaya (बर्सय) = A Rig Vedic god Tvashtri.
Now coming to explanation Paravatas (पारावत)
, it looks like the word is used in Rig-Veda in various contextes. There are various way in which the word paravata can be interpreted in a given sukta e.g. far away or distant places , name of the tribe living on the Banks of Saraswati , a mountain etc.
But if we look at all other translations like AWGP and Stavlekar and H.H. Wilson we find that they all three has interpreted this Paravatas as a mighty , forceful or rapid. So here in this particular sukta the word Paravatas is used not as a tribe but to denote the nature of the current of River Saraswati , which is mighty , forceful or rapid according to scholors.
This word Paravata is also used in another context in Rig Veda 5.52.11 as a distant or far away or remote place. But no one seems to says that the word means a RiG Vedic tribe here.
- So Brasaya is another name of vedic god Tvastar or Tvashtri.
- And the word Paravata in this perticular sukta denotes the nature of the waves , currents , rapids of river saraswati.