1.

Judge me, O LORD; for I have walked in mine integrity: I have trusted also in the LORD; therefore I shall not slide.

Title. of David = by David, or concerning the true David.
Judge me = Vindicate me, or Do me justice.
LORD. Hebrew. Jehovah. App-4 .
trusted = confided. Hebrew. batah. App-69 .

2.

Examine me, O LORD, and prove me; try my reins and my heart.

reins = kidneys.
reins . . . heart. Put by Figure of speech Metonymy (of Subject), App-6 , for thoughts and feelings.

3.

For thy lovingkindness is before mine eyes: and I have walked in thy truth.

walked = walked habitually.

4.

I have not sat with vain persons, neither will I go in with dissemblers.

5.

I have hated the congregation of evil doers; and will not sit with the wicked.

congregation = assembly: in its military aspect.
wicked = lawless. Hebrew. rasha' App-44 .

6.

I will wash mine hands in innocency: so will I compass thine altar, O LORD:

altar. No need to suppose this to refer to the Temple or later period than David. The altars of burnt offering and incense were in use from the time of the Exodus.

7.

That I may publish with the voice of thanksgiving, and tell of all thy wondrous works.

tell of = recount.

8.

LORD, I have loved the habitation of thy house, and the place where thine honour dwelleth.

habitation = dwelling: implying safety.
house. Referring not to the Temple, but to David's Tabernacle on Zion. Compare Psalms 5:7 , and see below.
the place, &c. = the place of Thy glorious Tabernacle.
dwelleth. Hebrew. shakan. See note on "placed" (Genesis 3:24 ).

9.

Gather not my soul with sinners, nor my life with bloody men:

Gather not = Destroy not. Hebrew. 'asaph. A Homonym. See note on "receive" (Numbers 12:14 , Numbers 12:15 ).
my soul = me (emphatic). Hebrew. nephesh. App-13 .

10.

In whose hands is mischief, and their right hand is full of bribes.

mischief = lewdness.

11.

But as for me, I will walk in mine integrity: redeem me, and be merciful unto me.

Redeem = deliver (by power). Hebrew. padah. See note on Psalms 25:22 .
be merciful = show me favour, or be gracious.

12.

My foot standeth in an even place: in the congregations will I bless the LORD.

congregations = assemblies; or plural of majesty = the great assembly. Occurs only here, and Psalms 68:26 .