Where does “bja” come from?

bja (Proto-Sino-Tibetan) comes from Norwegian Nynorsk brå, from French brave, from Italian bravo, from Vulgar Latin bravus, from Latin barbarus, from Ancient Greek βάρβαρος, from Proto-Indo-European balb-.

Ancestry of “bja”, step by step

Step	Language	Word	Meaning
1	Norwegian Nynorsk	brå	sudden
2	French	brave	brave; honest; hero
3	Italian	bravo	good, well-behaved; good, skilful, capable,...
4	Vulgar Latin	bravus	—
5	Latin	barbarus	foreign; savage; uncivilized
6	Ancient Greek	βάρβαρος	non-Greek-speaking, foreign; barbaric, brutal,...
7	Proto-Indo-European	balb-	—

Every word from Proto-Indo-European balb- →Every word from Ancient Greek βάρβαρος →Every word from Latin barbarus →