S'y frayer un chemin is an idiomatic expression that means "to make its way through" or "to forge a path". It implies overcoming obstacles or finding a way where there might not seem to be one.
In the song, Barbara Pravi sings, "La lumière se glisse partout où on lui laisse s'y frayer un chemin" (The light slips everywhere we let it make its way through). This beautiful imagery suggests that light, like hope or love, can penetrate even the darkest places if we allow it to, making it a profound and memorable phrase.
"Prière à la lumière" ("Prayer to the Light") is Barbara Pravi's own spoken prayer to light itself, asking it to move through her body and clear away the shadows she carries.
She asks for light to fill her eyes, replace her blood, and wrap her skin, images of purification and renewal rather than anything literal. The song reads as a quiet plea for peace and clarity in a hard moment.
In the chorus she opens her arms and hands, ready to receive that light so it can find its own way in. By the end she calls on it again, hoping it will help brighten what comes next.