Even the man of my peace. As the very height of all his miseries, David here declares that he had found the same treachery in some one, or, indeed, in many of his greatest friends. For the change of number is very frequent in the Hebrew language, so that he may speak of several individuals as if they were only one person. Thus the meaning would be: Not only the common people, or strangers of whom I had no knowledge or acquaintance, but my greatest friends, nay, even those with whom I was most intimate, and those of my own household, whom I admitted to eat and drink with me at my table, vaunt themselves reproachfully against me. Among the Hebrews, the expression, men of peace, denotes their kinsfolk and connections; but it was a much closer alliance, and one which ought to have secured a stricter observance of the laws of friendship, to eat the bread of David in company with himself: for it is as if he had employed the appellation, My companion. If, however, any would rather understand it of some particular traitor than of several persons, I have no objection to it. To lift up the heel is, in my opinion, to be understood metaphorically, and signifies to rise up disdainfully against a man who is afflicted and cast down. [1] Others explain the expression by to lay wait secretly; but the former interpretation is more appropriate, That the wicked, seeing that David was placed in embarrassed circumstances, or already prostrated in the dust, took occasion from this to assail him indirectly indeed, but, nevertheless, always with insolence; a thing which usually happens among people of a wicked and servile disposition. Christ, in quoting this passage, (John 13:18,) applies it to the person of Judas. And certainly we ought to understand that, although David speaks of himself in this psalm, yet he speaks not as a common and private person, but as one who represented the person of Christ, inasmuch as he was, as it were, the example after which the whole Church should be conformed -- a point well entitled to our attention, in order that each of us may prepare himself for the same condition. It was necessary that what was begun in David should be fully accomplished in Christ; and, therefore, it must of necessity come to pass, that the same thing should be fulfilled in each of his members, namely, that they should not only suffer from external violence and force, but also from internal foes, ever ready to betray them, even as Paul declares that the Church shall be assailed, not only by "fightings without," but also by "fears within," (2-Corinthians 7:5.)

Footnotes

1 - "Hath lifted against me his heel; i.e. hath spurned me, hath kicked at me, as a vicious beast of burden does, hath insulted me in my misery. Comp. Psalm 36:11." -- Cresswell.

Yea, mine own familiar friend - Margin, as in Hebrew: "the man of my peace." The man with whom I was at peace; who had no cause of alienation from me; with whom I was associated in the most peaceful and friendly relations.
In whom I trusted - He whom I made my confidential friend, and on whom I supposed I could rely in the time of trouble.
Which did eat of my bread - This may either denote one who was supported by him as one of his family, or else one who partook of his hospitality. In the former case, if that is the meaning, he bad a right to expect that, as a matter of gratitude, such an one would stand by him, and not be found among his enemies. In the latter case, if that is the meaning, he had a right to expect that one who had shared his hospitality would not be found among his foes.
Hath lifted up his heel against me - Margin, as in Hebrew: "magnified." So the Septuagint and the Latin Vulgate. Lather renders this, "hath trodden me under his feet." The figure here is taken from a horse that turns and kicks him that had fed him. This passage is applied John 13:18 to Judas, with the statement, in regard to him, that what he had done was done "that the Scripture might be fulfilled:" see the notes at that passage. It is not necessary to suppose that the Saviour meant to say that the passage in the psalm had original and exclusive reference to Judas; the phrase employed by the Saviour, "that the Scripture might be fulfilled," may have been used by him in that large sense in which these words are often used as denoting, either:
(a) that the language found in the Scriptures, and applicable originally to another case, "would properly express the idea," or describe the fact; or
(b) that the case referred to was one of a class; or that, as it was accomplished in the case of David, so in a similar sense it was accomplished in the case of the Saviour.
In other words, Judas was regarded as belonging to the same class as the individual to whom the psalm refers. He was one to whom the language of the psalm was applicable; and the Saviour endured the same kind of suffering which the person did who is referred to in the psalm. Thus the language of the Scriptures, applicable to all such cases, received a complete fulfillment in Him. It is remarkable that, in the reference to Judas, the Saviour quotes only a part of the verse: "He that eateth bread with me." He omits, apparently from design, the former part of the verse in the psalm, "mine own familiar friend, in whom I trusted," as if he would not even seem to convey the idea that he ever regarded Judas as his intimate friend, or as if he had ever really "trusted" him. He conveys the idea that Judas had partaken largely of his favors, but not that He himself was ever really a stranger to the baseness of his heart, John 6:64, John 6:70.

Mine own familiar friend - This is either a direct prophecy of the treachery of Judas, or it is a fact in David's distresses which our Lord found so similar to the falsity of his treacherous disciple, that he applies it to him, John 13:18. What we translate mine own familiar friend, איש שלומי ish shelomi, is the man of my peace. The man who, with the שלום לך shalom lecha, peace be to thee! kissed me; and thus gave the agreed-on signal to my murderers that I was the person whom they should seize, hold fast, and carry away.
Did eat of my bread - Was an inmate in my house. Applied by our Lord to Judas, when eating with him out of the same dish. See John 13:18, John 13:26. Possibly it may refer to Ahithophel, his counsellor, the man of his peace, his prime minister; who, we know, was the strength of Absalom's conspiracy.

Yea, mine own familiar friend, in whom I trusted, which did eat of my bread, (g) hath lifted up [his] heel against me.
(g) As David felt this falsehood, and as it was chiefly accomplished in Christ, (John 13:18) so shall his members continually prove the same.

Yea, mine own familiar friend,.... Or, "the man of my peace" (z); who did live peaceably with him, and ought always to have done so; whom he treated as his friend, as the rest of the apostles; calling him to that high office, and ordaining him to it, and qualifying him for it; and whom he called by the name of friend, when he came to betray him; Judas is meant;
in whom I trusted; with the bag and the money in it, both for the sustenance of his own family, the apostles, and for the relief of the poor, John 12:6;
which did eat of my bread; of his bread in common with the rest of the apostles; and who was eating with him when he gave the sign who should betray him; and who seems to have eaten of the bread in the Lord's supper: even this same person
hath lifted up his heel against me; by supplanting him, dealing hypocritically with him, and betraying him into the hands of his enemies: the metaphor is either taken from an unruly horse throwing his rider, and then ungenerously spurning at him, and trampling on him; or from wrestlers, who seek to supplant and trip up each other's heels; which shows the ingratitude, baseness, and treachery of Judas; see John 13:18.
(z) "vir pacis meae", Pagninus, Montanus, Vatablus, Cocceius, Gejerus, Michaelis.

mine . . . friend--literally, "the man of my peace."
eat . . . bread--who depended on me or was well treated by me.
hath lifted up heel--in scornful violence. As David and his fortunes typified Christ and His (compare Introduction), so these words expressed the treatment he received, and also that of his Son and Lord; hence, though not distinctly prophetical, our Saviour (John 13:18) applies them to Judas, "that the Scripture may be fulfilled." This last phrase has a wide use in the New Testament, and is not restricted to denote special prophecies.

Yea - These words were literally fulfilled in David, and yet the Holy Ghost looked farther in them, even to Christ and Judas, in whom they received a fuller accomplishment. Lift up - A phrase implying injury, joined with insolency and contempt; taken from an unruly horse, which kicks at him that owns and feeds him.