This is the Brothers Grimm version of the story and translated into English by Margarate Hunt.
The approximate narration time is 6 minutes
There were once two brothers, the one rich, the other poor. The rich one, however, gave nothing to the poor one, and he gained a scanty living by trading in corn, and often did so badly that he had no bread for his wife and children. Once when he was wheeling a barrow through the forest he saw, on one side of him, a great, bare, naked-looking mountain, and as he had never seen it before, he stood still and stared at it with amazement.
While he was thus standing he saw a twelve great, wild men coming towards him, and as he believed they were robbers he pushed his barrow into the thicket, climbed up a tree, and waited to see what would happen. The twelve men, however, went to the mountain and cried, "Semsi mountain, Semsi mountain, open," and immediately the barren mountain opened down the middle, and the twelve went into it, and as soon as they were within, it shut. After a short time, however, it opened again, and the men came forth carrying heavy sacks on their shoulders, and when they were all once more in the daylight they said, "Semsi mountain, Semsi mountain, shut thyself;" then the mountain closed together, and there was no longer any entrance to be seen to it, and the twelve went away.
When they were quite out of sight the poor man got down from the tree, and was curious to know what really was secretly hidden in the mountain. So he went up to it and said, "Semsi mountain, Semsi mountain, open," and the mountain opened to him also. The he went inside, and the whole mountain was a cavern full of silver and gold, and behind lay great piles of pearls and sparkling jewels, heaped up like corn. The poor man hardly knew what to do, and whether he might take any of these treasures for himself or not; but at last he filled his pockets with gold, but he left the pearls and precious stones where they were. When he came out again he also said, "Semsi mountain, Semsi mountain, shut thyself;" and the mountain closed itself, and he went home with his barrow.
And now he had no more cause for anxiety, but could buy bread for his wife and children with his gold, and wine into the bargain. He lived joyously and uprightly, gave help to the poor, and did good to every one.
When, however, the money came to an end he went to his brother, borrowed a measure that held a bushel, and brought himself some more, but did not touch any of the most valuable things. When for the third time he wanted to fetch something, he again borrowed the measure of his brother. The rich man had, however, long been envious of his brother's possessions, and of the handsome way of living which he had set on foot, and could not understand from whence the riches came, and what his brother wanted with the measure. Then he thought of a cunning trick, and covered the bottom of the measure with pitch, and when he got the measure back a piece of money was sticking in it. He at once went to his brother and asked him, "What hast thou been measuring in the bushel measure?" - "Corn and barley," said the other. Then he showed him the piece of money, and threatened that if he did not tell the truth he would accuse him before a court of justice. The poor man then told him everything, just as it happened. The rich man, however, ordered his carriage to be made ready, and drove away, resolved to use the opportunity better than his brother had done, and to bring back with him quite different treasures.
When he came to the mountain he cried, "Semsi mountain, Semsi mountain, open." The mountain opened, and he went inside it. There lay the treasures all before him, and for a long time he did not know which to clutch at first. At length he loaded himself with as many precious stones as he could carry. He wished to carry his burden outside, but, as his heart and soul were entirely full of the treasures, he had forgotten the name of the mountain, and cried, "Simeli mountain, Simeli mountain, open." That, however, was not the right name, and the mountain never stirred, but remained shut. Then he was alarmed, but the longer he thought about it the more his thoughts confused themselves, and his treasures were no more of any use to him. In the evening the mountain opened, and the twelve robbers came in, and when they saw him they laughed, and cried out, "Bird, have we caught thee at last! Didst thou think we had never noticed that thou hadst been in here twice? We could not catch thee then; this third time thou shalt not get out again!" Then he cried, "It was not I, it was my brother," but let him beg for his life and say what he would, they cut his head off.
KHM: Kinder- und Hausmärchen (Children's and Household Tales)