The Strathclyde Motets are communion motets setting propers of the mass for various Sundays and feasts. They are suitable for intermediate standard choirs. This piece is an antiphon for 21st December, the text (in English) is one of the Great O antiphons which are used on the seven days approaching Christmas.

The same text is used in another MacMillan antiphon, O, for choir, trumpet and strings (vocal score available as 979-0-060-12023-7).