1.

LORD, my heart is not haughty, nor mine eyes lofty: neither do I exercise myself in great matters, or in things too high for me.

Title. A Song of degrees. Same as Psalms 120 . App-67 .
of David = by David. For its place here see App-67 .
LORD. Hebrew. Jehovah. App-4 .
high = wonderful.

2.

Surely I have behaved and quieted myself, as a child that is weaned of his mother: my soul is even as a weaned child.

Surely = [See] whether I have not, &c.
quieted = silenced. Some codices, with Septuagint and Vulgate, read "soothed and uplifted": i.e. comforted.
myself = my soul. Hebrew. nephesh.
My soul = Myself. Hebrew. nephesh . App-13 .

3.

Let Israel hope in the LORD from henceforth and for ever.

Israel. Not "a liturgical addition", but used to link the three Psalms of this group together (Psalms 129:1 ; Psalms 130:7 , Psalms 130:8 ; Psalms 131:3 ). For Israel is to find rest and peace where their kings (David, and Hezekiah) found it.