1.

LORD, I cry unto thee: make haste unto me; give ear unto my voice, when I cry unto thee.

Title. A Psalm of David. See Title of 140.
LORD. Hebrew. Jehovah. App-4 .

2.

Let my prayer be set forth before thee as incense; and the lifting up of my hands as the evening sacrifice.

incense. Compare Exodus 30:7 . Revelation 8:3 , Revelation 8:4 .
sacrifice = gift offering. App-43 .

3.

Set a watch, O LORD, before my mouth; keep the door of my lips.

Set a watch = Set a guard. Hebrew. shamrah. Same word as "keep", Psalms 141:9 Occurs only here.
Keep = keep in safety. Not the same word as in Psalms 141:9 .

4.

Incline not my heart to any evil thing, to practise wicked works with men that work iniquity: and let me not eat of their dainties.

evil. Hebrew. ra'a'. App-44 .
wicked. Hebrew. rasha'. App-44 .
men. Hebrew. 'ish . App-14 .
iniquity. Hebrew. 'avert. App-44 .
eat: i.e. partake of, or have fellowship with.
dainties = pleasant things. Compare Psalms 141:6 .

5.

Let the righteous smite me; it shall be a kindness: and let him reprove me; it shall be an excellent oil, which shall not break my head: for yet my prayer also shall be in their calamities.

the righteous = a righteous one.
an excellent oil = oil for the head. This verse is said to be "extremely obscure" and "corrupt to a degree". The Figure of speech Metalepsis ( App-6 ) makes all clear; "head", being first used for hair , and then for the whole person by Figure of speech Synecdoche (of the Part). Hebrew = "as oil on the hair, I will not refuse it". Note the alternation of lines in this verse.
yet. Same root as "withal" in Psalms 141:10 .

6.

When their judges are overthrown in stony places, they shall hear my words; for they are sweet.

When. Not in Hebrew text.
judges = rulers. Compare 2 Kings 9:33 .
in stony places = as by a rock; or, over a rock. Hebrew by the hands of a rock.
They: i.e. the people.
words = sayings. Hebrew. 'imrah. App-73 .
sweet. Cognate with "dainties", Psalms 141:4 .

7.

Our bones are scattered at the grave's mouth, as when one cutteth and cleaveth wood upon the earth.

Our bones. Septuagint (Vatican B, and Alex. A by second hand), Syriac, Arabic, and Ethiop. read "their bones"
the grave's. Hebrew Sheol's. App-35 . Note the word "bones" in this connection.
cutteth = sliceth, as in 1 Samuel 30:12 .Song of Solomon 4:3 ; Song of Solomon 6:7 (elsewhere rendered "piece" or "pieces"). Never means "ploweth", as in Revised Version.
cleaveth. As in Ecclesiastes 10:9 . Zechariah 14:4 (compare Genesis 22:3 . 1 Samuel 6:14 ).

8.

But mine eyes are unto thee, O GOD the Lord: in thee is my trust; leave not my soul destitute.

GOD the Lord. Hebrew. Jehovah. Adonai. App-4 .
is my trust = have I sought refuge. Hebrew. hasah. App-69 .
my soul = me (emphatic). Hebrew. nephesh. App-13 .

9.

Keep me from the snares which they have laid for me, and the gins of the workers of iniquity.

Keep. Same root as "watch"in Psalms 141:3 . (Hebrew. shamreni.)
snares. Authorized Version, 1611, read "snares" (singular) Since 1769, "snares" (plural) Hebrew text is singular.
gins = traps. Short for "engine" = an ingenious contrivance. "

10.

Let the wicked fall into their own nets, whilst that I withal escape.

the wicked = lawless ones. Hebrew. rasha'. App-44 .
withal = Same as "yet", Psalms 141:5 .
escape = pass on [in safety].