This is a David Haas song for Eucharist in the style of a Taize chant.
The verses are for a cantor and they overlap the ostinato refrain in such a way that the refrain looks like it has to be done in between each verse so the assembly just keeps going with the refrain under the verses and between the verses.
The sheet music can be purchased at GIA where the text is hidden in their preview.
This gives a better idea of the song.