Yancy provides an analogy to the supposed imprecise fulfillment of the prophecies. Imagine a 5 year old boy in the year 1900 whose father promises him his own horse and buggy when he turns 21. Then, in 1916, the father buys his son a brand new model-T Ford instead. Would the son be sad because he did not get the promised horse and buggy? Or would he be thrilled that his father had satisfied his transportation needs in the best way possible at the time?
In this story the father is God. He is omniscient. So he would have known exactly what was going to happen. Yet, that initial promise, made when the child was 5, was made in terms which could be understood by the child then. If the father had promised a model-T Ford to the child, it would have seemed fantastical and futuristic. The child would not have understood what was being promised and would not have appreciated it.
This post was inspired by "The Bible Jesus Read" by Philip Yancy.