Ансамбль Сирин "Моя душа грешная" "My Sinful Soul"

This is Church Slavonic - ancient Russian, actually. This is, so to say, a song of repentance in Orthodox tradition, though such versicles are folk art and never were sung in the Divine service - only in common everyday life, in monasteries during daily chores, in villages during long Polar nights, by wandering singers and so on.