AND THERE IS NO CREATURE HIDDEN FROM HIS SIGHT: kai ouk estin (3SPAI) ktisis aphanes enopion autou: (1 Samuel 16:7; 1 Chronicles 28:9; 2 Chronicles 6:30; Psalms 7:9; 33:13-15; 44:21; 90:8; 139:11; Psalms 139:12; Proverbs 15:3,11; Jeremiah 17:10,23,24; John 2:24; 21:17; 1 Corinthians 4:5; Revelation 2:23)

No (3756) (ou) means absolutely no. No exceptions here!

Creature (2937) (ktisis from ktízo = create, form or found) stresses work of original formation of object and represents something which has undergone a process of creation.

Hidden (852) (aphanes from a = without + phaíno = to appear) means literally not appearing and so not manifest or non-apparent, concealed, invisible. Unable to be known about. God's microscope can lay bare the smallest microbe of doubt and sin.

Sight (1799) (enopion from en = in + ops = ace, eye, countenance) means in the face of, in front of,  before, in the sight of

BUT ALL THINGS ARE OPEN AND LAID BARE: panta de gumna kai tetrachlismena (RPPNPN): (Job 26:6; 34:21; 38:17)

All (pas) means all without exception and amplifies "no" exceptions mentioned in the first part of this verse.

Open (1131) (gumnos) means not covered, nude or naked but  not necessarily descriptive of absolute nakedness as it was used of a person wearing only an undertunic. As such it could mean one who was comparatively naked or scantily dressed. It was used of one poorly dressed (James 2:15). Figuratively in this verse it means uncovered, manifest, disclosed, exposed, not hidden and easy to be known.

Both soul and body are naked to the eye of God. As it is the same sun that melts the wax which hardens the clay, so it is the same Word of God that leads some on to salvation, and turns others who will have none of it away into outer darkness.

Barclay explains that...

What he is saying is that as far as men are concerned we may be able to wear our outward trappings and disguises; but in the presence of God these things are stripped away and we have to meet him as we are. (Barclay, W: The Daily Study Bible Series. The Westminster Press or Logos)

Guzik writes that open or...

Naked reminds us of the way God saw through Adam’s feeble hiding. God sees through our hiding the same way. (David Guzik. The Enduring Word Commentary Series)

Laid bare (5136) (trachelizo from trachelos = neck) means to bend back the neck as the surgeon does for operating, as the anesthesiologist does that he might be able to see the vocal cords thus enabling him to insert the tube that conducts life giving oxygen thru the airway!

It may refer to the wrestler’s art of seizing one by the throat, rendering him limp and powerless.

Trachelizo was also used to describes the bending back of the neck of an animal to be slaughtered for an offering in order to expose the throat.

Figuratively as used here trachelizo means to lay bare or open.

Wuest writes that trachelizo

means “to seize and twist the neck or throat.” It was used of combatants who handled their antagonists in that way. It meant also “to bend back the neck of the victim to be slain, to lay bare or expose by bending back.” Hence the verb came to mean “to lay bare, to uncover, to expose.” (Wuest, K. S. Wuest's Word Studies from the Greek New Testament: Eerdmans or Logos)

Vincent adds that...

The exact metaphor, however, it is impossible to determine. The following are the principal explanations proposed: taken by the throat, as an athlete grasps an adversary; exposed, as a malefactor’s neck is bent back, and his face exposed to the spectators; or, as the necks of victims at the altar are drawn back and exposed to the knife. The idea at the root seems to be the bending back of the neck, and the last explanation, better than any other, suits the previous figure of the sword. The custom of drawing back the victim’s neck for sacrifice is familiar to all classical students. See Hom. Il. i. 459; ii. 422; Pindar, Ol. xiii. 114. The victim’s throat bared to the sacrificial knife is a powerful figure of the complete exposure of all created intelligence to the eye of him whose word is as a two-edged sword. (Vincent, M. R. (2002). Word Studies in the New Testament 4:429)

Friberg writes that trachelizo means...

strictly take hold of by the neck; only passive in the NT, as a metaphor drawn from ancient custom, either of making an enemy face his conquerors by a sword fixed under his chin, of fastening a lock grip on an opponent in wrestling, or of bending back the head of a sacrificial victim, ready for the knife be exposed, i.e. be easily known. (Friberg, T., Friberg, B., & Miller, N. F. Analytical Lexicon of the Greek New Testament. Baker Academic)

Vine writes that trachelizo...

literally means to have the throat exposed. It is taken from the games, and signified to bend back the neck. Here the metaphor may be taken either from the sacrifice of a victim or from a mode of punishment. Whatever the metaphorical sense is, the warning is that there is no hiding oneself in any part of our being from God. (Vine, W. Collected writings of W. E. Vine. Nashville: Thomas Nelson or Logos)

Hebrews 4:13 is the only NT use.

The perfect tense pictures this as a permanent state.

MacArthur adds that trachelizo had two distinct uses in ancient times:

It was used of a wrestler taking his opponent by the throat. In this position the two men were unavoidably face to face. The other use was in regard to a criminal trial. A sharp dagger would be bound to the neck of the accused, with the point just below his chin, so that he could not bow his head, but had to face the court. Both uses had to do with grave face-to-face situations. When an unbeliever comes under the scrutiny of God’s Word, he will be unavoidably face-to-face with the perfect truth about God and about himself. (MacArthur, John: Hebrews. Moody Press or Logos)

Thayer has the following entry for trachelizo...

1. to seize and twist the neck or throat; used of combatants who handle thus their antagonists (Philo, Plutarch, Diogenes Laërt, others). 2. to bend back the neck of the victim to be slain, to lay bare or expose by bending back; hence, tropically, to lay bare, uncover, expose

God's sharp Word shows us where we are wrong not only in what we do, but in how we think and feel. We would like to hide our guilt but we cannot. God has perfect knowledge of what is going on in His world, even to the point of knowing the very thoughts of our hearts. This calls us to repent before we have to face the final judgment.

Barnes writes that...

The design of the remark here is, to guard those to whom the apostle was writing from self-deception --since they could conceal nothing from God.  (Albert Barnes. Barnes NT Commentary)

Barclay summarizes the three potential meanings of trachelizo writing...

(i) It was a wrestler’s word and was used for seizing an opponent by the throat in such a way that he could not move. We may escape God for long enough but in the end he grips us in such a way that we cannot help meeting him face to face. God is one issue that no man can finally evade.

(ii) It was the word that was used for flaying animals. Animals were hung up and the hide was taken off them. Men may judge us by our outer conduct and appearance but God sees into the inmost secrets of our hearts.

(iii) Sometimes when a criminal was being led to judgment or to execution, a dagger, with point upwards, was so fixed below his chin that he could not bow his head in concealment but had to keep it up so that all could see his face and know his dishonour. When that was done, a man was said to be tetrachēlismenos. In the end we have to meet the eyes of God. We may avert our gaze from people we are ashamed to meet; but we are compelled to look God in the face.

Kermit Eby writes in The God in You: “At some time or other, a man must stop running from himself and his God—possibly because there is just no other place to run to.” There comes a time to every man when he has to meet that God from whose eyes nothing ever can be concealed (Barclay, W: The Daily Study Bible Series. The Westminster Press or Logos)

TO THE EYES OF HIM WITH WHOM WE HAVE TO DO: tois opthalmois autou pros on emin ho logos: (Ecclesiastes 12:14; Matthew 7:21,22; 25:31,32; John 5:22-29; Acts 17:31; Romans 2:16; Romans 14:9-12; 2 Corinthians 5:10; Revelation 20:11-15)

To the eyes (3788) (ophthalmos) anthropomorphic description of God, Who sees all and knows all. You cannot hide, be you a saved or unsaved sinner.

God's eyes see all the facts in our inmost hearts. Surely every servant of Christ today needs to gaze into this revealing mirror and be honest with himself and God.

To do (3056) (logos) means account or something said. Literally it says "to whom the account is to us", "to whom is our word" or "with whom our matter is". The idea is with whom our final reckoning has to be made.

The ESV and the NIV render it...

to whom we must give account.

Guzik exhorts us to...

Remember the context. The writer to the Hebrews trusts that he has pierced the hearts of his audience, who were contemplating “giving up” on Jesus. In this passage, he has made it plain that they can’t give up on Jesus can keep it “hidden” from God. The word of God has discovered and exposed their condition. (David Guzik. The Enduring Word Commentary Series)

Ryrie writes that it is

A play on the Greek term for "word"; i.e., if our lives conform to "the word of God" (v. 12), then our word (account) in the day of judgment will be acceptable to God. (The Ryrie Study Bible: New American Standard Translation: 1995. Moody Publishers)

Other versions offer an easier to understand rendering -

NKJV: "to Whom we [must] [give] account"

NIV: "to whom we must give account"

NLT = "This is the God to Whom we must explain all that we have done."

We must give a personal account to God for what we have said and done in our own lives. A personal relationship to God requires personal responsibility. Everyone, including believers (not to pay for our sins for our sins have been paid for! How did we redeem the time He gave us?, etc.), must render an account to God for the life lived on earth. This should motivate us to obedience realizing nothing can be concealed from Him. (See note Romans 14:12)