this canticle is from the book of the prophet Isaiah, and is found at Isaiah 12:2–6. it is used on monday mornings by the episcopal church.
surely, it is God who saves me;
i will trust in him and not be afraid.
for the Lord is my stronghold and my sure defense,
and he will be my Savior.
therefore you shall draw water with rejoicing
from the springs of salvation.
and on that day you shall say,
give thanks to the Lord and call upon his Name;
make his deeds known among the peoples;
see that they remember that his Name is exalted.
sing the praises of the Lord, for he has done great things,
and this is known in all the world.
cry aloud, inhabitants of zion, ring out your joy,
for the great one in the midst of you is the Holy One of Israel.