Have you noticed how everything seems to take 40 whatever? Noah's ark was afloat for 40 days and 40 nights; the Israelites wandered for 40 years; Jesus was tested in the desert for 40 days. The reason for this is that the Bible is steeped in literary devices and symbolism. 40 is the number of divine testing. So perhaps they didn't last 40 days or years, but they lasted an indeterminate amount of time that was sufficient enough to test those involved.
The Hebrews were crazy about their literary devices. Everything meant something. There has been huge debate between rabbis as to why the first letter of the Book of Genesis is Bet (the second of the Hebrew alphabet) and not Alef (the first). Even the word count was significant. Quite often stories would be symmetrical, with the beginnings having the same amount of words as the end. The climax would happen bang in the middle. As an English Literature graduate this little facts get me ridiculously excited.
So here are some of my favourite literary devices in the Bible:
This comes from the Greek word for the letter X. It's where a point is emphasised when two or more related clauses (parts of a sentence) are repeated but in reverse. One of the most obvious examples in the Bible is in Matthew 19:30, "But many who are first will be last, and many who are last will be first." The ideas of coming first then last in the first part of the sentence are reversed in the second part. Other examples include the first part of Genesis 9:6; Isaiah 6:10; Isaiah 2:3-5 (although the pattern isn't quite as expected); and 2 Timothy 2:8-10 (this one you'll have to look carefully, or just use wikipedia).
Again, elements of the first bit of the sentence are repeated, but in the correct order. An example of this is Matthew 7:7-8: "Ask and it will be given to you; seek and you will find; knock and the door will be opened to you. For everyone who asks receives; the one who seeks finds; and to the one who knocks, the door will be opened."
The Bible is rich with various images. It has some of the most beautiful poetic passages in literature. The Book of Psalms is just littered with references to skies, seas, animals, towers, storms. The SOng of Songs is a poem with, again, many beautiful similes and metaphors. Some of the most interesting phrases and powerful images in the images originate from the Bible: "through the glass darkly", "a broken heart", "a nest of vipers".