this canticle is from the book of the prophet Isaiah, and is found at Isaiah 60:1–22. it is used on wednesday mornings by the episcopal church, and on sundays in advent.

the version here is that used by the episcopal church, which is a bit shorter than the biblical text.

arise, shine, for your light has come,
    and the glory of the Lord has dawned upon you.
for behold, darkness covers the land;
    deep gloom enshrouds the peoples.
but over you the Lord will rise,
    and his glory will appear upon you.
nations will stream to your light,
    and kings to the brightness of your dawning.
your gates will always be open;
    by day or night they will never be shut.
they will call you, the city of the Lord,
    the zion of the Holy One of Israel.
violence will no more be heard in your lard,
    ruin or destruction within your borders.
you will call your walls, salvation,
    and all your portals, praise.
the sun will no more be your light by day;
    by night you will not need the brightness of the moon.
the Lord will be your everlasting light,
    and your God will be your glory.