Q. One of my co-workers recently asked why 40 days is such a significant number in the Bible. All I have found says that when God wants to make a great change in someone's life He did it after 40 days. Noah was in the ark for 40 days and 40 nights, and the Isrealites were in the desert for 40 years. Could someone please let me know why the number 40 is so significant?

A.  In his comprehensive article on "Number, Numbering, Numbers" in the Interpreter's Dictionary of the Bible, biblical scholar M. H. Pope surveys the numerous texts in which the number 40 (a multiple of 4, "a sacred number the world over" as well as in Scripture) occurs. He writes, "Of the multiples of four, the most significant as a symbolic and sacred number is forty. It is used as a round number to designate a fairly long period of time in terms of human existence or endurance." On the basis of Pope's article and usage he cites, it would seem that the number 40 would signify not change, but prolongation and extension of time.

Most public libraries have a copy of the four-volume set of the IDB. Rather than cite the many texts here, I would encourage you to read Pope's article in Volume 3, pages 561-67 (esp. 565). I think that you will find it most instructive and interesting.