Old East Slavic съпаси богъ

← Old East Slavic съпасти (mention)

← Old East Slavic богъ (mention)

← Proto-Slavic *sъ(n) (affix)

← Proto-Slavic *pasti (affix)

← Proto-Slavic *bȍgъ (inherited)

→ Lithuanian ačiū (mention)

→ Russian спасибо (inherited)

→ Ukrainian спасибі (inherited)