John Calvin Commentary Psalms 41:9

"Yea, mine own familiar friend, in whom I trusted, Who did eat of my bread, Hath lifted up his heel against me." — Psalms 41:9 (ASV)

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 someone, 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, indeed, 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, exalt themselves insolently against me.

Among the Hebrews, the expression, men of peace, denotes their relatives 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 with him: for it is as if he had used the title, 'My companion.'

If, however, anyone prefers to understand it as referring to a particular traitor rather than 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.

Others explain the expression by to lay wait secretly; but the former interpretation is more appropriate: namely, that the wicked, seeing that David was placed in difficult circumstances, or already prostrated in the dust, took this as an opportunity to assail him indirectly, yet always with insolence. This is something that usually happens among people of a wicked and servile disposition.

Christ, in quoting this passage (John 13:18), applies it to Judas. And certainly, we should understand that, although David speaks of himself in this psalm, he does not speak as an ordinary, private individual, but as one who represented Christ, since he was, so to speak, the example after which the whole Church should be patterned—a point well deserving our attention, so 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 necessarily 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, just as Paul declares that the Church will be assailed, not only by fightings without, but also by fears within (2 Corinthians 7:5).