Psalm In exitu Israel, with antiphon Deus autem noster
To the tonus peregrinus
Fifth psalm at Vespers on Sundays (Gregorian)
The psalm In exitu Israel was sung to a special psalm tone which stood outside the modal system, and was called the tonus peregrinus. This tone was used for no other text and was exceptional in having different reciting notes for each half of the verses.
Antiphon – Deus autem noster
Deus autem noster in caelo: omnia quaecumque voluit fecit.
Our God is even in heaven: whatsoever He has wished, He has made.