I was intrigued by his use of Psalm 139:18b (Ps. 138 in the LXX/Vulgate tradition) as a point of departure:
Resurrexi et adhuc tecum sum – I have risen, I am still with you, for ever. These words, taken from an ancient version of Psalm 138 (v. 18b), were sung at the beginning of today’s Mass. In them, at the rising of the Easter sun, the Church recognizes the voice of Jesus himself who, on rising from death, turns to the Father filled with gladness and love, and exclaims: My Father, here I am! I have risen, I am still with you, and so I shall be for ever; your Spirit never abandoned me. In this way we can also come to a new understanding of other passages from the psalm: “If I climb the heavens, you are there; if I descend into the underworld, you are there … Even darkness is not dark for you, and the night is as clear as day; for you, darkness is like light” (Ps 138:8,12).
This is as sensitive a modern exposition of the Christological sensus plenior as you could ask for; and I am increasingly convinced that this kind of exegesis is (and should) be making a comeback within the church.
But, being who I am, I am most interested in the textual question. The sentence resurrexi et adhuc tecum sum corresponds to הקיצתי ועודי עמך in the Masoretic text, "I awoke and still I am with you." Resurrexi, "I rose again" is an interesting interpretation of the Hebrew "I awoke." In this case it is probably mediated via the Septuagint translation ἐξηγέρθην, which could be taken either as "I woke up" or "I rose up." In fact, even the Hebrew word (derived from the root קיץ) could plausibly be connected with awaking from the sleep of death, as in Isa. 26:19, Jer. 51:39, Job 14:12, and Dan. 12:2. So resurrexi is not necessarily a far-fetched translation.
But whose translation is it? The text of the Easter Introit in the Mass at St. Peter's is derived from one of the oldest of the Latin translations of the Psalter, the Psalterium Romanum, which is St. Jerome's first revision of the Old Latin translation. In this case, resurrexi is probably left over from the Old Latin, and not from Jerome's revision. A later revision of Jerome's, the Psalterium Gallicanum, reads exsurrexi, which is more unambiguously "I rose/stood up" without the overtones of resurrection. His last version of the Psalter, rendered directly from the Hebrew (iuxta Hebraeos), reads evigilavi, "I woke up."
But many of today's translations read completely differently. For instance, the JPS translates, "I end — but am still with You." The NRSV has "I come to the end—I am still with you." In fact, the "Neo-Vulgate," sanctioned by the Vatican reads si ad finem pervenerim, adhuc sum tecum. This stems from a hypothesis that הקיצתי should be derived from a root קצץ, "to come to an end" (see BHS and HALOT).
I must admit I don't agree with or even understand this hypothesis. For one thing, the proposed root is otherwise unattested in verbal form. Plus, none of the ancient versions understand the verb in this way. The whole context is as follows (from the NRSV):
I try to count them—they are more than the sand;
I come to the end—I am still with you.
"Them" refers to "God's thoughts," which v. 18a says are "more than the sand," i.e. literally innumerable. The modern emendation actually suggests that the psalmist can number God's thoughts, and come to the end of them. But surely this is against the whole tenor of the passage (and the psalm as a whole)?
The psalm as a whole is based on the idea of God's limitlessness. He is everywhere, and his thoughts exceed human comprehension. This couplet in that context has to mean this: (a) God's thoughts surpass human limitations; they cannot be counted; (b) God's presence is not conditioned by human weakness; the psalmist sleeps and then awakes, but God's presence does not waver and wane in the same way. "When I wake up, I am still with thee." Thus even the literal sense is not altogether foreign from Benedict's homiletical interpretation.