“All have seen,” etc.–This story the Master told whilst staying at Jetavana, on the Chapter about the Judas tree 1.
Four Brothers, approaching the Tathāgata, asked him to explain the means by which ecstasy may be induced. This he explained. This done, they dispersed to the several places where they spent their nights and days. One of them, having learnt the Six Spheres of Touch, became a saint; another did so after learning the Five Elements of Being, the third after learning the Four Principal Elements, the fourth after learning the Eighteen Constituents of Being. Each of them recounted to the Master the particular excellence which he had attained. A thought came into the mind of one of them; and he asked the Master, “There is only one Nirvana for all these modes of meditation; how is it that all of them lead to sainthood?” Then the Master asked, “Is not this like the people who saw the Judas tree?” As they requested him to tell them about it, he repeated a tale of bygone days.
Once on a time Brahmadatta the king of Benares had four sons. One day they sent for the charioteer, and said to him,
“We want to see a Judas tree; show us one!”
“Very well, I will,” the charioteer replied. But he did not show it to them all together. He took the eldest at once to the forest in the chariot, and showed him the tree at the time when the buds were just sprouting from the stem. To the second he showed it when the leaves were green, to the third at the time of blossoming, and to the fourth when it was bearing fruit.
After this it happened that the four brothers were sitting together, and some one asked, “What sort of a tree is the Judas tree?” Then the first brother answered,
“Like a burnt stump!”
And the second cried, “Like a banyan tree!”
And the third–“Like a piece of meat 1!”
And the fourth said, “Like the acacia!”
They were vexed at each other’s answers, and ran to find their father. “My lord,” they asked, “what sort of a tree is the Judas tree?”
“What did you say to that?” he asked. They told him the manner of their answers. Said the king,
“All four of you have seen the tree. Only when the charioteer showed you the tree, you did not ask him ‘What is the tree like at such a time?’  or ‘at such another time?’ You made no distinctions, and that is the reason of your mistake.” And he repeated the first stanza
“All have seen the Judas tree–
What is your perplexity?
No one asked the charioteer
What its form the livelong year!”
The Master, having explained the matter, then addressed the Brethren: “Now as the four brothers, because they did not make a distinction and ask, fell in doubt about the tree, so you have fallen in doubt about the right”: and in his perfect wisdom he uttered the second verse:
“Who know the right with some deficiency
Feel doubt, like those four brothers with the tree.”
When this discourse was ended, the Master identified the Birth: “At that time I was the king of Benares.”
184:1 Kiṁsuka = Butea Frondosa.
185:1 It has pink flowers.