Here is what the late Tabarsi has said in Majma'-al-Bayan...

Here is what the late Tabarsi has said in Majma'-al-Bayan: There was a man among the Muslims who had a palm tree, a branch of which was bent towards the house of a poor man who had a large family. Sometimes the owner of the palm tree would collect the fruit and if by chance some dates fell in the poor man's yard and his children picked them up, the owner would come and snatch them away from their hands and even from their mouths.

The poor man complained to the holy Prophet (S) who, in turn requested that the man leave until he (S) could investigate the situation. Then, it happened that the Prophet (S) met the owner of the palm tree and asked him if he would give him (the holy Prophet) the tree in question, in return for a palm tree in Paradise. The man declined with the plea that the dates of that tree, among all his numerous trees, were so delicate that he could not give it up.

There was another man, according to some narrations, named Ahul-Dahdah, who heard what the holy Prophet (S) promised the owner. He said, “O Messenger of Allah! Would you promise the same to me if I get the palm tree from the owner and give it to you?" The holy Prophet (S) said, “Yes".

So, the man went to the owner of the palm and talked with him and questioned him as to if he knew that the Prophet (S) had offered a palm tree in Paradise instead of the one he had and he answered that he had many palm trees but, the taste of the dates of that tree was the most delicious. Then, the man asked the owner whether he wanted to sell it, and he refused unless he received a sum that he supposed no one would pay.

The man asked about the price and the owner answered that it was forty palm trees. The buyer was astonished and told him that it was an expensive price that he demanded for a bent palm tree-forty palm trees! Then, after a short pause the buyer agreed to give him forty palm trees. The greedy seller asked him to call some people as witnesses for the exchange and the buyer did. After that, he went to the holy Prophet (S) and presented the palm tree to him.

The Messenger of Allah went to the poor man and told him that the palm tree was in his and his children's possession. It was there that Surah Lail was descended and stated what it declared about the righteous and the wrongdoers. Piety and the Divine Assistance At the beginning of this Surah, again, we find three reflective oaths about the 'creation' and the Creator of the world.