"In the souls of the people the grapes of wrath are filling and growing heavy, growing heavy for the vintage." - Steinbeck
The title of his novel was taken from the Battle Hymn of the Republic, by Julia Ward Howe ("Mine eyes have seen the glory of the coming of the Lord, He is trampling out the vintage where the grapes of wrath are stored, He has loosed the fateful lightning of His terrible swift sword, His truth is marching on").
The phrase "grapes of wrath" sound like something Biblical. I have my Strong's exahaustive concordance opened in front of me, and I have read all the verses listed under grapes, grape and wrath and there is only one verse in The Book of Revelation which reads speaks of "the great winepress of the wrath of God" (Ch. 14, verse 19). My mother was always sickly and would complain that she looks like "the wrath of God" (or sometimes "the wreck of Hesperus") whenever anyone threatened to visit.
Steinbeck has a long passage, early in the book I believe, about a turtle struggling to cross the road. The turtle carries with it, stuck to its shell, a seed of grain.
Of course, this passage is intended by Steinbeck to be very symbolic.
The turtle's struggle symbolizes persistence and suffering and survival. Seeds of grain are ancient symbols of life, of dying and then bearing fruit.
Later in the novel Ma Joad states:
“You got to have patience. Why Tom – us people will go on livin’ when all them people is gone. Why, Tom, we’re the people that live. They ain’t gonna wipe us out. Why, we’re the people – we go on.”
Tom makes a curiously Christ-like statement to Ma Joad: “Whenever they’s a fight so hungry people can eat, I’ll be there. Whenever they’s a cop beatin’ up a guy, I’ll be there . . . . I’ll be in the way guys yell when they’re mad an’—I’ll be in the way kids laugh when they’re hungry an’ they know supper’s ready. An’ when our folks eat the stuff they raise an’ live in the houses they build—why, I’ll be there.”
An symbolism is used in the Old Testament which is analogous. Steinbeck may well have been aware of this passage since he seems to have had an extensive knowlege of the Bible. The family name Joad bears a striking resemblence to the Biblical name Job.
I have to check this, but from memory, it is in the book of the Prophet Ezekiel, in chapter 4. According to the story, the prophet is commanded to take a tablet of clay or stone, and draw upon it a diagram of Jerusalem, and then lay upon the ground for literally hundreds of days, and play, symbolically, as if he is laying seige to Jerusalem.
"Take a clay tablet, put it in front of you and draw the city of Jerusalem on it. Then lay siege to it: Erect siege works against it, build a ramp up to it, set up camps against it and put battering rams around it. Then take an iron pan, place it as an iron wall between you and the city and turn your face toward it. It will be under siege, and you shall besiege it. This will be a sign ... "
I believe that the function of such ancient and mythic symbolism has found its way into literary craft.
Steinbeck's turtle and seed of grain is very much like Ezekiel's clay tablet.
Someone once asked Akira Kurosawa regarding the symbolism and meaning of "Seven Samurai". Kurosawa replied that if "a meaning" was of importance, then he would not have made the movie, but would have simply held up a sign with "the meaning" written upon it.
Why are symbols and parables so important to us? Why can't we always just hold up a sign with "the meaning" on it, plain for all to see?
We may reflect upon this excerpt from Steinbeck's 1962 speech accepting the Nobel Prize for Literature:
“The writer is charged with exposing our many grievous faults and failures for the purpose of improvement….Furthermore, the writer is delegated to declare and celebrate Man’s proven capacity for greatness of heart and spirit – for gallantry in defeat, courage, compassion and love. In the endless war against weakness and despair, these are the bright rally flags of hope and emulation. I hold that a writer who does not passionately believe in the perfectability of man has no dedication nor any membership in literature.”
The connection of all human life is one of the novel’s dominant themes.
A few years ago, a total stranger read things I had posted on the internet, and wrote me a long E-mail, ending with this well-known quote from The Grapes of Wrath
“Before I knowed it, I was sayin’ out loud, ‘The hell with it! There ain’t no sin and there ain’t no virtue. There’s just stuff people do. It’s all part of the same thing.’ . . . . I says, ‘What’s this call, this sperit?’ An’ I says, ‘It’s love. I love people so much I’m fit to bust, sometimes.’ . . . . I figgered, ‘Why do we got to hang it on God or Jesus? Maybe,’ I figgered, ‘maybe it’s all men an’ all women we love; maybe that’s the Holy Sperit—the human sperit—the whole shebang. Maybe all men got one big soul ever’body’s a part of.’ Now I sat there thinkin’ it, an’ all of a suddent—I knew it. I knew it so deep down that it was true, and I still know it.”
- Jim Casy, Chapter 4 (It may be significant that Jim Casy's initials are "J.C.", which can bring to mind Jesus Christ.)
This stranger had read my accounts of my life in a Greek monastery, and how I slowly drifted away to other beliefs, other interests, other ways of life. One famous iconographer, whom I worked with, left that monastery and went to Colorado, to found his own monastery. This stranger wrote me to say that he had spent time in Colorado, with that iconographer, and had experienced many of the exact same changes and disillusionments as I described in my posts. His life and my life had evolved in an uncanny parallel fashion. For him, that Steinbeck quote summed up how he felt.
Perhaps it's a stretch, but I see a similarity between Abel's blood being spilled into the soil along with that of the blood of Tom's friend's father. The friend muses about sticking his hand in the same area where his father's blood was spilled and appears to want some reassurance that he won't go crazy or be cursed as a result. 
