There are two translations below. The first comes from an ESV Bible. The second is my own "wooden" translation of the same verses, organized according to its own literary structure (without verse numbers). Following that is my commentary on this portion of Psalm 119.
Psalm 119 (ESV)
169 Let my cry come before you, O Lord;
give me understanding according to your word!
170 Let my plea come before you;
deliver me according to your word.
171 My lips will pour forth praise,
for you teach me your statutes.
172 My tongue will sing of your word,
for all your commandments are right.
173 Let your hand be ready to help me,
for I have chosen your precepts.
174 I long for your salvation, O Lord,
and your law is my delight.
175 Let my soul live and praise you,
and let your rules help me.
176 I have gone astray like a lost sheep; seek your servant,
for I do not forget your commandments.
A) Let my cry draw near before your face, O Yahweh.
B) According to your commanded-word, give me discernment!
A’) Let my plea enter before your face.
B’) According to your spoken-word, rescue me!
C) My lips will burst forth a song of praise because you instruct me in your written-laws!
C’) My tongue will shout jubilantly of your spoken-word because all your regulations are just!
D) Let your hand be to my succor, because I have chosen your directions.
E) I long for your deliverance, O Yahweh, and your Law is my delight!
D’) Let my soul revive so that it can praise you, and let your judgments succor me.
E’) I have wandered like a lost sheep; so search for your servant because I do not forget your commandments
The first line of the first verse (in the ESV) says, "Let my cry come before you," whereas the first line of the second verse says "Let my plea come before you." Clearly those two statements parallel each other. And at first glance, the only noticeable difference between the two is the word cry and the word plea. But the ESV translation is actually misleading. According to the more "wooden" translation above, what King David actually wrote in the first verse (and yes, I do believe King David wrote this Psalm) was "let my cry draw near...". In the second verse, David wrote something different. He wrote, "let my plea enter...". And so, the difference is not merely between crying and pleading (as the ESV suggests), but also between drawing near and entering.
At a second glance, you might be thinking that there still isn't much of a difference between drawing near and entering; but according to the culture in which King David was raised, such distinctions were profoundly important. The word for "drawing near" is קרב (qrb), and has a peculiar importance within the Law of God, particularly because it is frequently used throughout the book of Leviticus. Just to show a small sample of how frequent qrb is, below is another "wooden" translation, only this one shows the first few verses of Leviticus. Notice the frequency of the qrb root:
Now he called to Moses. Yahweh spoke to him from the Tent-of-Congregation, saying: "Speak to the children of Israel and say to them: 'When anyone among you brings-near (qrb) a near-offering (qrb) for YHWH, from domestic animals, from the herd or from the flock you may bring-near (qrb) your near-offering (qrb). If an ascension-offering is his near-offering (qrb) from the herd, then a male, without blemish, let him bring-it-near (qrb) to the entrance of the Tent-of-Congregation, let him bring-it-near (qrb) as acceptance for him, before the presence of Yahweh.'"
According to God's Law, certain boundaries were set by God for worshiping-laymen such as David. David understood that once he entered the courtyard surrounding the Lord's house (the tabernacle), that would be as far as he could "draw near." If he desired to draw near further, and enter into the Lord's holy presence, he would die. And not by his own choice, of course, but because God's Law taught him so. God's Law taught him how polluted he was because of sin, how holy God was, and how pure one needed to be in order to enter the very presence of God. But the Lord, full of grace and mercy, placed Himself in a covenant with man and allowed an animal without blemish to represent everyone who desired to draw near. In order to draw near, that animal would have to die in his (or her) place and be carried by a priest before the altar. In doing so, that animal-representative would draw near before Yahweh. If David were offering an animal without blemish, that animal would die and draw near before the face of Yahweh in David's place. And so, when King David asked Yahweh for his cry to draw near before His face, David was using sacrificial terminology. David was, in essence, saying, "Let this cry of mine be received as a sacrifice, brought near before you according to your Law."
Similar but distinguishable terminology is also used in the second verse, when David describes the entrance, the בוֹא (b'wa), of his plea. Just as Moses alone entered (b'wa) the cloud of Yahweh at the top of Mount Sinai (Ex. 24:18) and the cloud of Yahweh covering the Tabernacle (Ex. 33:9), so the High Priest only entered (b'wa) the Most Holy Place of Yahweh in the Tabernacle (Lev. 16:17). David's plea, therefore, is distinguishable from his cry. David wants his cry, his wailing, to draw near as a sacrificial offering without blemish, and he wants his plea to actually enter the most holy presence of God. While acknowledging the holy boundaries of access to God, David embraces God as one to whom he can draw near and actually enter before. Through faith, David embraces the gracious character of God revealed in his Law.
But for what does David cry? And for what does David plea?
Again, we find another misleading translation in the ESV. The ESV doesn't distinguish what "word" David trusts in. In the second line of the first two verses, the ESV says "according to your word," with no distinction between either verse. But in Hebrew, the first verse says "according to your commanded-word" (דָבָר dbr), whereas the second verse says "according to your spoken-word" (אמרה imrh). The first "word," dbr, is very common. It's most familiar use is with the ten commandments, the ten commanded-words, the ten dbr's. The other word, imrh, refers to that which God has spoken, which is why it's often translated as God's "promise" throughout the Scriptures. Elsewhere in this Psalm, it is translated as "promise" (119:38, 41, 50, 58, 76, 82, 116, 123, 133, 140, 148, 154; ESV). I have only translated it as God's spoken-word to distinguish it from God's commanded-word.
And so, what David cries out to Yahweh for is understanding, or discernment, according to Yahweh's commanded-word. And what he pleads for is deliverance, or rescuing, according to Yahweh's spoken, or promised, word. Two important principles for Christian living can be deduced from this: First, it teaches us not to presume upon God's deliverance in all circumstances, but to find assurance in those promises which God has spoken. And secondarily, it teaches us David's priorities in prayer.
Let's look at both of these principles in more detail.
According to the first principle, we learn that David was not pleading for deliverance apart from something God had spoken to him--something God had promised him. Such a promise, in the context of David's life, is obviously that which was spoken in 1st Samuel 16, when God provided for Himself a king among the sons of Jesse, David by name. From that time on, David was the Lord's anointed, not Saul, and Saul treated David's anointing as a threat to his own throne. This means that within the historical setting behind the scenery of Psalm 119:169-176, David is pleading for the Lord to rescue him at a time when David felt his life and throne was in jeopardy. God had anointed him and filled him with His Holy Spirit, yet David was on the run from King Saul who was trying to kill him and keep him from ever ascending the throne of Israel. This time is generally understood to be around the events recorded in I Samuel 23.
The second principle we learn involves David's priorities. Here we see a pattern of thought in David. If these historical circumstances are true, as I have argued them to be, notice carefully that David does not simply plea for God to rescue him. Nor does David plea for rescuing first. Ordinarily, when a Christian finds himself in extremely stressful and even dangerous circumstances (like David's), the first desire of the heart is for God to get us out of trouble. Ordinarily, we don't want any more stress, which means we don't want the headaches of learning to endure trials. We want out! We want deliverance from our troubles. We don't want to learn what to do next as we endure trials. But that was not David's first priority. David's first priority was to learn discernment according to God's commanded-word. David's first priority was to learn more about what he could do to please God through his trials. David's first priority was to understand what he ought to do (and not do) through in his present trial, as he awaited deliverance. David's other priority--his plea--was for deliverance, and that was a secondary priority because he trusted, by faith, in God's promise; which means he trusted God's faithfulness. He trusted in God's faithful character because he learned God's holy character from His Law. It was God's holy Law which gave him hope and taught him to fear God and His holy boundaries. It was the work of God's Holy Spirit that ennobled his heart to trust and obey faithfully, and maintain such holy priorities, even through such difficult trials.
David's great confidence in the Lord is made clear in the central section of this Psalm (sections C and C'). David knows the day is coming when his own lips will burst forth with a song of praise. David looks forward to shouting jubilantly before all of Israel about God's spoken-word, i.e. God's promise to him. Yet notice carefully that David's confidence is grounded in God's written laws (section C). David knows that all of God's regulations for living are just (C'), and therefore he has nothing to fear. If God is for him, who would be so foolish as to be against him? Historically we know that King Saul was that foolish.
In sections D and D', David refers to God's "hand" and His "judgments" succoring him. This brings us back to David's first priority--David's cry. David is being hunted by Saul, but David knows that God has spoken to him, promising him the throne of Israel; and David cries for discernment according to God's commanded-word. David cries for such discernment because he doesn't want to displease the Lord and foolishly presume that God's hand would not be against him too, especially if he chose a path of lawlessness and sinful behavior (like Saul did) to get out of his troubles. David understood that God's covenant involves both blessings and curses--blessings of God's hand for faithful obedience and the curses of God's hand for disobedience. And here we learn that David sees God's hand of judgment as a good thing for him. It's a good thing for him because his first priority is to discern God's commanded-word and obey it. Why should David fear God's hand of judgment if he is doing those things which please God? David should have nothing to fear because he had chosen Yahweh's directions and his delight was in Yahweh's Law (sections D and E).
Finally, David closes with these words: "I have wandered like a lost sheep; so search for your servant..."
Many commentators suggest that David is confessing his private, and even ignorant, sins. That is to say, David is pouring out his heart and soul, confessing every possible sin imaginable, even secret sins which caused him to wander away from the faith. This, allegedly, is what he meant by wandering like a lost sheep. But is that really what's being taught here? Is David acknowledging that he has wandered, however slightly, from the faith? Such an interpretation would be odd and unnecessary. It would be odd because David's final words are "search for your servant because I do not forget your commandments." If David was confessing that he had wandered from the faith, however slight, that would seem to conflict with his confidence that he has not forgotten God's commandments. It also would conflict with the many other repeated statements about loving and keeping God's commandments.
Instead, what I believe David is expressing is his vulnerability. David is describing a familiar scene to shepherds like himself. The scene is of a "lost" or "perishing" sheep in unfamiliar territory--a territory where enemies surround him and where he is not safe. Therefore David cries out, "I have wandered...so search for your servant." This fits well within the historical setting described above. David is in distress and danger, on the run for his life from king Saul. Nevertheless, David trusts in God's promises concerning his kingdom. David finds comfort in the Lord's anointing. David draws near before the face of God in prayer, and because his pleading actually entered the Most Holy Place, the Lord sought his servant. That God of peace and Great Shepherd of the sheep made him complete in every good work to do his will, working in him what was well-pleasing in his sight. To Him belongs the glory for ever and ever. Amen.