I will wash my hands in purity. Referring, in these words, to the ordinary use of the sacrifices, he makes a distinction between himself and those who professed to offer the same divine worship, and thrust themselves forward in the services of the sanctuary, as if they alone had the sole right to perform them. As David, therefore, and these hypocrites were one in this respect, that they entered the sanctuary, and surrounded the sacred altar together, he proceeds to show that he was a true worshipper, declaring, that he not only diligently attended to the external rites, but came to worship God with unfeigned devotion. It is obvious that he alludes to the solemn rite of washing which was practiced under the law. [1] He, accordingly, reproves the gross superstition of hypocrites, who in seeking only the purification of water, neglected true purification; whereas it was God's design, in the appointment of the outward sign, to put men in mind of their inward pollution, and thus to encourage them to repentance. The outward washing alone, instead of profiting hypocrites, kept them at a greater distance from God. When the Psalmist, therefore, says, I will wash my hands in innocence, he intimates that they only gather more pollution and filth by their washings. The Hebrew word nqyvn, nikkayon, signifies the cleanness of any thing, and is figuratively used for innocence. We thus see, that as hypocrites derive no moral purity whatever from their washings, David mocks at the labor with which they vainly toil and torment themselves in such rites. However high, therefore, the wicked may be exalted in the Church, and though crowds of them should fill our sanctuaries, let us, after the example of David, celebrate the outward profession of our faith in such a manner as not deceitfully to substitute its external rites in the room of true devotion. Thus shall we be pure and free from all stain of wickedness. Moreover, as the people were not permitted to touch the altar, David uses the word encompass. [2]

Footnotes

1 - The washing of the hands in solemn protestation of innocence, on particular occasions, was enjoined by the Mosaic ritual, and was common among the Jews, Deuteronomy 21:6, 7. It was in common use among them before prayer; and the priests, in particular, were not to perform any sacred office in the sanctuary until they had poured water from the laver, which was set in the temple for that purpose, and washed their hands, Exodus 40:30-33.

2 - Mudge conjectures that the expression, encompass, is probably taken from the custom of forming a ring round the altar at the time of worship. And Goodwyn informs us, that at the feast of tabernacles the people, on the seventh day, encompassed the altar seven times, carrying branches of palm trees in their hands in remembrance of the overthrow of Jericho, and singing hosannas. -- Moses and Aaron, p. 132. David, however, may refer to the practice of the priests, who, when they offered sacrifices, went round about the altar; and his meaning may simply be, that as the priests first washed their hands, and then performed their sacred office at the altar; so he deeply felt the necessity of personal purity, in order to his engaging in the service of God.

I will wash mine hands in innocency - The psalmist here refers, as another evidence of his piety, to the fact that it was a ruling purpose of his life to be pure, to worship and serve his Maker in purity. He had stated that he had no sympathy with the wicked, and that he did not make them his companions; he now states what his preferences were, and where his heart was to be found. He had loved, and he still loved the worship of God; he delighted in the pure service of the Most High. Washing the hands is an emblem of purity. So Pilate Matthew 27:24 "took water, and washed his hands before the multitude, saying, I am innocent of the blood of this just person." Compare Deuteronomy 21:6-7. The word rendered "innocency" means properly "cleanness, purity;" and perhaps the allusion here is to water that is perfectly pure. The sense of the passage is, that he would endeavor to make himself pure, and would thus worship God. He would not come, practicing iniquity, or cherishing sin in his heart. He would banish all from his mind and heart and life that was wrong, and would come with true love to God, and with the spirit of a sincere worshipper.
So will I compass thine altar, O Lord - In this manner, and with this spirit, I will worship thee. The word "compass" may either mean that he would "embrace" it by throwing his arms around it, or that he would "go round" it with others in a solemn procession in worship. The idea is, that he would come to the altar of God with his offering in sincerity and truth. It was to himself one evidence of sincere piety that he so purposed in his heart, or that he was conscious of a desire to worship God in purity and truth. This desire is always an indication of true piety.

I will wash mine hands in innocency - Washing the hands was frequent among the Jews, and was sometimes an action by which a man declared his innocence of any base or wicked transaction. This Pilate did, to protest his innocence of the mal-treatment and death of Christ. I will maintain that innocence of life in which I have hitherto walked; and take care that nothing shall be found in my heart or life that would prevent me from using the most holy ordinance, or worshipping thee in spirit and truth.
So wilt I compass thine altar - It is a mark of respect among the Hindoos to walk several times round a superior, and round a temple.

I will (e) wash mine hands in innocency: so will I compass thine altar, O LORD:
(e) I will serve you with a pure affection, and with the godly that sacrifice to you.

I will wash my hands in innocency,.... The Vulgate Latin version renders it, "among innocent persons"; men of a holy harmless life and conversation; with these he determined to converse in common, and not with such as before described; or the sense is, that he would wash his hands, in token of his innocence, integrity, and uprightness, he had before spoke of, and of his having nothing to do with such evil men as now mentioned; see Deuteronomy 21:6; "hands" are the instrument of action, and to "wash" them may design the performance of good works, Job 9:30; and to do this "in innocency", or "purity", may signify the performance of them from a pure heart, a good conscience, and faith unfeigned; and particularly may have some respect to the lifting up of holy hands in prayer to God, previous to public worship; there seems to be an allusion to the priests washing their hands before they offered sacrifice, Exodus 30:19;
so will I compass thine altar, O Lord; frequent the house of God, where the altar was, and constantly attend the worship and ordinances of God; the work of the altar being put for the whole of divine service; the altar of burnt offering is here meant, which was a type of Christ; see Hebrews 13:10; reference is had to the priests at the altar, who used to go round it, when they laid the sacrifice on the altar, and bound it to the horns of it, at the four corners, and there sprinkled and poured out the blood; compare Psalm 43:4; in order to which they washed their hands, as before; and in later times it was usual with the Heathens (y) to wash their hands before divine service.
(y) "----pura cum veste venito, et manibus puris sumite fontis aquam, nunc lavabo ut rem divinam faciam", Tibull. l. 2. eleg. 1. Plantus in Aullular. Acts. 3. Sc. 6. Vide Homer. Odyss, 12. v. 336, 337.

wash mine hands--expressive symbol of freedom from sinful acts (compare Matthew 27:24).

The poet supports his petition by declaring his motive to be his love for the sanctuary of God, from which he is now far removed, without any fault of his own. The coloured future ואסבבה, distinct from ואסבבה (vid., on Psalm 3:6 and Psalm 73:16), can only mean, in this passage, et ambiam, and not et ambibam as it does in a different connection (Isaiah 43:26, cf. Judges 6:9); it is the emotional continuation (cf. Psalm 27:6; Song 7:12; Isaiah 1:24; Isaiah 5:19, and frequently) of the plain and uncoloured expression ארחץ. He wishes to wash his hands in innocence (בּ of the state that is meant to be attested by the action), and compass (Psalm 59:7) the altar of Jahve. That which is elsewhere a symbolic act (Deuteronomy 21:6, cf. Matthew 27:24), is in this instance only a rhetorical figure made use of to confess his consciousness of innocence; and it naturally assumes this form (cf. Psalm 73:13) from the idea of the priest washing his hands preparatory to the service of the altar (Exodus 32:20.) being associated with the idea of the altar. And, in general, the expression of Psalm 26:6. takes a priestly form, without exceeding that which the ritual admits of, by virtue of the consciousness of being themselves priests which appertained even to the Israelitish laity (Exodus 19:16). For סבב can be used even of half encompassing as it were like a semi-circle (Genesis 2:11; Numbers 21:4), no matter whether it be in the immediate vicinity of, or at a prescribed distance from, the central point. לשׁמע is a syncopated and defectively written Hiph., for להשׁמיע, like לשׁמד, Isaiah 23:11. Instead of לשׁמע קול תּודה, "to cause the voice of thanksgiving to be heard," since השׁמיע is used absolutely (1-Chronicles 15:19; 2-Chronicles 5:13) and the object is conceived of as the instrument of the act (Ges. 138, 1, rem. 3), it is "in order to strike in with the voice of thanksgiving." In the expression "all Thy wondrous works" is included the latest of these, to which the voice of thanksgiving especially refers, viz., the bringing of him home from the exile he had suffered from Absolom. Longing to be back again he longs most of all for the gorgeous services in the house of his God, which are performed around the altar of the outer court; for he loves the habitation of the house of God, the place, where His doxa, - revealed on earth, and in fact revealed in grace, - has taken up its abode. ma`own does not mean refuge, shelter (Hupfeld), - for although it may obtain this meaning from the context, it has nothing whatever to do with Arab. ‛ân, med. Waw, in the signification to help (whence ma‛ûn, ma‛ûne, ma‛âne, help, assistance, succour or support), - but place, dwelling, habitation, like the Arabic ma‛ân, which the Kamus explains by menzil, a place to settle down in, and explains etymologically by Arab. mḥll 'l-‛ı̂n, i.e., "a spot on which the eye rests as an object of sight;" for in the Arabic ma‛ân is traced back to Arab. ‛ân, med. Je, as is seen from the phrase hum minka bi-ma‛ânin, i.e., they are from thee on a point of sight (= on a spot where thou canst see them from the spot on which thou standest). The signification place, sojourn, abode (Targ. מדור) is undoubted; the primary meaning of the root is, however, questionable.

Compass - Approach to thine altar with my sacrifices: which I could not do with any comfort, if I were conscious of those crimes, whereof mine enemies accuse me.