Rev, certain, probable, and possible
    The "Certain"
    
    A fulfillment of prophecy can only be regarded as certain, for
    our finite and imperfect minds, when the fulfillment has already come about, or
    when its terms are absolutely incapable of any meaning save one; both factors
    would make our assurance doubly sure. Thus, we know that 2Sa 7:12-16 and its
    counterpart in 1Ch 17:11-14 were in part fulfilled in Solomon, because David so
    understood it in part (1Ch 28:6), as did Solomon himself (2Ch 6:9-11). We know
    that it was not entirely fulfilled in Solomon because David clearly looked
    beyond Solomon's time (2Sa 7:19), and because the New Testament tells us
    explicitly that it referred to Jesus (Acts 13:33; Heb 1:5). Again, we know that
    the Bible promises the literal return of the Jews to the land of Israel, and of
    the Lord Jesus Christ to the earth, and many other such things plainly taught in
    Scripture because the terms of these prophecies do not admit of any other
    faithful interpretation.
    
    The "Probable"
    
    A fulfillment can be regarded as probable when the events we
    see in history are seen to correspond closely with the terms of a prophecy.
    Thus, it is hard to see that we could be mistaken in regarding the presence of
    some millions of Jews in the Holy Land today as, in part at least, a fulfillment
    of the prophecies of their return. It is probable, too, that this heralds the
    near return of the Lord. Some prophecies about the return of Israel to the land
    contain such apparently plain indications that they must suffer great
    afflictions before the final deliverance from their enemies (Eze 36-39; Zec 14),
    that we consider it probable that they will in fact suffer in this
    way.
    
    The "Possible"
    
    Things "possible" may have all degrees of likelihood from high
    probability to being highly unlikely, and the decision we come to in any
    particular case is bound to be in some degree subjective. We can hardly expect
    absolute unanimity, even among those sharing the same doctrinal foundation.
    Thus... it is possible to regard the "sun, moon and stars" of Rev 6:12,13 as
    referring to the nation of Israel; it is also possible to doubt this, since the
    symbols are certainly not invariably used in this sense in Scripture. Which
    conclusion we come to (if we come to a precise conclusion at all) is not,
    however, of the first importance, since other passages state in plain terms what
    may or may not here be intended by the symbols. 
    
    Indeed, it is not at all unlikely that we are sometimes moved
    to understand symbols in a particular way because we have already concluded on
    what are quite different grounds that certain things are true: in that event it
    is not the symbols which are teaching us, but we who are reading (right or
    wrong) our own meaning into them. This fault is more common than we sometimes
    realize, and we should be on our guard against it.
    
    Within the category of "possible", too, must be put all
    detailed predictions of things yet future which are not most categorically
    defined in Scripture itself -- unless, indeed, our predictions are so outrageous
    as not to be thought possible at all. And in view of the fact that the New
    Testament often provides us with interpretations of Old Testament prophecies
    which we should not have thought of for ourselves (such as those of Hos 11:1 in
    Mat 2:15; and of Jer 31:15 in Mat 2:18), we need to be very careful before we
    pronounce any interpretation impossible. Even so, since it required the guidance
    of the Holy Spirit to enable New Testament writers to offer such interpretations
    to us, we might feel that our own feet should re-main firmly on the ground when
    we are disposed to adventure our own understanding of Scripture's
    prophecies.
    
    Since [in interpreting prophecy] we will be meeting events
    which certainly lie, in the future... it follows that detailed interpretations
    are bound to be speculative in some degree, even when they are offered at all.
    It might even be that no detailed interpretation is possible. But this is not in
    itself to be regarded as any weakness in the expository basis: it may simply be
    that information is inadequate for any assurance as to the meaning until the
    events have actually occurred.
    
    To this it cannot properly be objected that a prophecy which
    one can only understand when it has happened is of little use. For in the first
    place its general tenor may be plain even when the detail is not; and in the
    second place it can be very valuable and reassuring to know that we have reached
    a certain point in the fulfillment of God's purpose, and can look forward now to
    the next stage.
    
    (NRev 131-133).