The passage from Ezekiel I had in mind was 31:1-6, 10-14. The Psalm, verses from 92, is quoted in full in the text below. The Gospel is Mark 4:26-34.
I love this parable, because it is a sign of Jesus' sense of humor, something that simply doesn't convey from one culture to another very well, and something we also simply don't associate with divinity. Gods, we are certain, are serious, and since humor is so dangerous (involving, as it always does, a disparity in situation, in power, in position, at some level simply mockery), we don't like to associate it with the divine: unless we are imagining a capricious god who is like the wanton boys, and to whom we are but flies. Not an image, certainly, that we associate with Jesus.
Humor is dangerous because it is subversive, and subversive always requires a superior position from which you undermine the position of the object of the joke. The one standing on the rug is superior until the one who yanks it away proves that superiority illusionary. So it is with humor; which is why it is so dangerous: it asserts a new status quo, and does so in a way that implies that we, too, could be the butt of the joke. So when Jesus compares the kingdom of heaven to a mustard seed, and describes the mustard bush as "the greatest of all shrubs" that "puts for large branches," we nod sagely and consider the majesty of the kingdom, even as we have to admit we know nothing about mustard plants, and can't quite reconcile talk of shrubs with "large branches." But it can't be a joke, so we struggle to take it seriously.
The story is quite distinctive; so much so, that it made its way into all three synoptics, and even into the Gospel of Thomas (20). But those writers understood the strangeness of the story better than we do, and beefed up the punchline for their audiences. For Mark, the mustard plant is a shrub, but the largest of plants; for Matthew, it becomes "the largest of garden plants," and both Matthew and Luke call it a "tree" (Matthew 13:32, Luke 13:19). In Thomas, it is a "large plant." (Thomas 20). Comparable, one might say, to the cedars of Lebanon.
Cedar, of course, was the wood of kings. Jeremiah notes that the king builds a palace for himself of cedar; but he neglects the people, the poor, the widow, the orphan; he prefers his cedar lined palace to justice, and so he loses everything. The mighty cedars of Lebanon were metaphors of royal power. That is clear from what Ezekiel says:
Consider Assyria, a cedar of Lebanon, with fair branches and forest shade, and of great height, its tops among the clouds....All the birds of hte aird made their nests in its boughs; under its branches all the animals of the field gave birth to their young; and in it shade all great nations lived.But what happened?
Because it towered so high and set its top among the clouds, and its heart was proud of its height, I gave it into the hand of the prince of the nations; he has dealt with it as its wickedness deserves. I have cast it out. Foreigners from the most terrible of the nations have cut it down and left it.And how is the kingdom of God like that?
This is a declaration of judgment, not a praise of majesty. Consider that the audience for Jesus' parable would have had this image in mind, including the stern rebuke taught by Ezekiel: pride, as the Greeks would have said among the Hebrews of Jewish Palestine, goeth before a fall. Hubris was what the gods punished, and the Hellenistic world of Palestine Judea would have understood that lesson from both cultural directions, and have absorbed it. But surely the basiliea tou theou would be the most majestic of kingdoms, the most powerful of empires. How, then, can it be compared to amustard plant, a shrub, a weed, which brings the birds to the garden to eat the seeds the farmer has just planted? The garden, after all, is the place of order, where only what you want grown should come up. The problem with the mustard seed is that it is so small, so easily lost in the seeds you want to grow, and then it is an unwanted plant (and what is a "weed" but an undesired plant in an underisable location?), and worse, it brings birds, which eat the seeds and the other plants.
And even worse, it's a shrub, not even a bush, not even a shade tree. It's a nuisance, and, so far as I know, until the French learned to made mustard from it, a useless plant.
So how is the kingdom of God like that?
That's one direction for the parable: the comparison to Ezekiel is the other. It was hubris, pride in their own accomplishment rather than thanksgiving to God, which caused the Assyrian cedar to fall. The kingdom of God avoids that error. It has nothing to boast of. It does not pierce the clouds. It does not tower high above the trees of the field; it does not provide shade, or even room for birds to nest. Birds gather in its branches, the better to plunder the garden, but in that it is only an accomplice to disorder and disruption and ruined plans. But it certainly gives no reason for arrogance.
So how is the kingdom of God like that?
Consider it a place as recommended by the psalmist:
It is good to give thanks to the Lord,
and to sing praises to your Name, O Most High;
To tell of your loving-kindness early in the morning
And of your faithfulness in the night season;
On the psaltery and on the lyre,
and to the melody of the harp.
For you have made me glad by your acts, O Lord;
and I shout for joy because of the works of your hands.
The righteous shall flourish like a palm tree,
and shall spread abroad like a cedar of Lebanon.
Those who are planted in the house of the Lord
shall flourish in the courts of our God;
They shall still bear fruit in old age;
they shall be green and succulent;
They they may show how upright the Lord is,
my Rock, in whom there is no fault.
Now first, consider what those words do not say: they do not say God seeks praise, demands praise, insists on praise. God is not Zeus; God is neither petty nor arrogant. Praise is due to God for what God has done, and praise is due to God to keep the creature always mindful of who is Most High, of who is Creator, and from whom all things come. The cedar of Lebanon fell because of arrogance, not because of the jealousy of the Creator. God is praised for loving-kindness and faithfulness, for keeping trust and always showing love. And those who are directed toward God, and away from the value they place on their own works, are like Abraham and Sarah, like Manoah and his wife, the parents of Samson; like Elkanah and Hannah, the parents of Samuel; like Zechariah and Elizabeth, the parents of John, the Baptizer. They still bear fruit in old age; they are green and succulent. They show how upright the Lord is, who in loving-kindness is faithful to them.
Far better that the kingdom of God should look like that: where the first are last, and the last first. Where, if we think our food and our livelihood is secured by our own hand, by the work we do in our garden, our plans will be undone, and we will be directed, again and again, to rely on God, to put our faith and our trust in our Creator.
Which is something of a lead-in, actually. On the topics of faith and belief, I have much to say; soon, I hope.