The Book of PsalmsPsalm 131
In the Douay-Rheims and other Bibles that follow the Vulgate, this is Psalm 130. Read it in the Douay-Rheims.

131
A Song of Ascents. By David.
LORD, my heart isn’t arrogant, nor my eyes lofty;
nor do I concern myself with great matters,
or things too wonderful for me.
2Surely I have stilled and quieted my soul,
like a weaned child with his mother,
like a weaned child is my soul within me.
3Israel, hope in the LORD,
from this time forward and forever more.