Allegory is only a legitimate form of interpretation when used by other biblical writers. They are the only ones with the proper access to determine whether or not another passage had any type of meaning beyond that which is plain. Our own text book makes a very good point regarding this matter, “To ascribe hidden meanings to Scripture, a person assumes an authority equivalent to or superseding that of the author.”[i] The biblical writers are safe here because the same Holy Spirit that moved the prophets of Old moved the writers of the New. So the Holy Spirit would know, as would Jesus, whether there was some meaning to the Scriptures beyond what was clear. For us to claim any meaning beyond the plain, besides that which is alluded to in Scripture itself, would imply that we had some access to either the writer or the Holy Spirit that other saints aren't privileged enough to enjoy. This does not even consider the dangers that reside in the lack of accountability that comes with taking the liberty to ascribe meaning to any passage based on nothing more than a “holy hunch.” When it comes to interpreting Scripture we must consider what has been given rather than fooling around with what has not.
[i] McQuilkin, Robertson. Understanding and Applying the Bible. Illinois: Moody Publishers, 2009. p. 41
[i] McQuilkin, Robertson. Understanding and Applying the Bible. Illinois: Moody Publishers, 2009. p. 41