1 Peter 1:11

searching what time or what manner of time the Spirit of Christ which was in them did point unto, when it testified beforehand the sufferings of Christ, and the glories that should follow them.

The exact nature of the puzzlement of the prophets is here given. It regarded the "time" of the marvelous events which they foretold. The exact answer to their questionings, however, was not revealed to them, only that it was not scheduled for their own generation, but for subsequent ages.

The phenomenon of prophets not being able to comprehend fully their own writings is one of utmost consequence in biblical interpretation; for it requires the deduction that the Spirit of Christ, speaking through them, did not merely give them the correct ideas, or thoughts, which they then were to present in their own words, but, contrarily, the words of truth were exactly what they did receive, words with ideas and thoughts contained which they did not understand at all! It is a mystery why many modern commentators deny a proposition like this, especially in view of the fact that the apostle Peter himself, on Pentecost, uttered the words of God, which he did not at all fully comprehend at the time, the vital truth that the promises of the gospel are for "them that are afar off," clearly meaning, in retrospect, the Gentiles, but in no manner being fully understood by Peter at the time he spoke this. One may legitimately wonder if Peter's analysis of his own example in this did not likewise reveal to him what had happened in the case of the ancient prophets of the old dispensation, leading to the truth uttered here.

The Spirit of Christ which was in them ... The Spirit of Christ here is the "Holy Spirit," who was also called by this title by Paul (Romans 8:9); and there are deductions of vast consequences which are mandated by this:

In attributing the teaching of the prophets to the Spirit of Christ, Peter is in effect affirming that the same Spirit which spoke through him and the other apostles also spoke through the Old Testament prophets (compare 2 Peter 1:21)[34]

Macknight gave as the meaning of this verse the observation that:

From this it appears that, in many instances, the prophets did not understand the meaning of their own prophecies, but studied them, as others did, with great care, in order to find out.[35]

[34] Raymond C. Kelcy, op. cit., p. 28.

[35] James Macknight, op. cit., p. 439.