An excerpt from "From the Mouth of God" by Sinclair B. Ferguson
The cord in the story of Rahab? It was a cord. She was not saved because the cord was scarlet, or because it represented the blood of Christ, but because she placed her destiny in the hands of the covenant God of Abraham, Isaac and Jacob and threw in her lot with his covenant people. He is indeed the God who promised to send Christ and to bless the nations of the earth through the seed of Eve and Abraham. But had the cord been green, or even black, it would have made no difference to its ‘meaning’. But because it is scarlet, by association of ideas it has come to be understood as symbolic of the blood of Christ. Colour association is, however, an unreliable principle of interpretation.
Similarly, we are not meant to see in Mephibosheth’s double lameness a potted systematic theology, but to admire the care and mercy of God flowing through his servant David, and of the importance of remaining faithful to one’s vows and promises. Ultimately that does lead us to Christ, David’s greater Son. But we get to him by seeing this passage in its broader redemptive context, not by reading the passage as though it were a metaphor for something else.
I recall hearing of a Professor of Old Testament Studies who, in the course of a lecture on Exodus 38, asked his students what they thought was the ‘meaning’ of the various pegs or pins God commanded to be made for the tabernacle. His eager students sought to outdo each other in deep spiritual explanations. Eventually the shrewd Professor said, ‘Ah, yes, of course. But could it just possibly be, gentlemen, that some of these tent pegs were there to hold up the tent?’!
Over the centuries, both in private and public interpretation of the Bible, this approach has been commonplace, and at times it has been dominant. Many Christians simply inherit it in the context in which they are spiritually nurtured. That is one reason it is so important for us to give some attention to how we approach understanding the Bible.
Paul laid down an important axiom for Timothy: ‘Do your best to present yourself to God as one approved, a worker who has no need to be ashamed, rightly handling the word of truth.’1 We are to work at Bible study. And therefore we need to learn to know how to interpret the Bible properly.
1) 2 Tim. 2:15