Source: Adapted from a Sicha of the Lubavitcher Rebbe:
"From The Rebbe's Treasure" - Students of Seminary Bais Menachem, Montreal CanadaThe Talmud in Moed Kotton discusses the true meaning of blessings. The following story is told:
Rabbi Yonasson ben Asmai and Rabbi Yehuda ben Gerim had been studying the chapter concerning vows in the presence of Rabbi Shimon Bar Yochai. In the evening they took leave of him.... He then said to his son: "These are worthy men. Go and let them bestow a blessing upon you."
His son went... Then they turned to him (the son) and said "Why did you come to us?"
"Father sent me here to receive your blessing" was his answer.
Whereupon they said to him: "May it be His will that thou sowest and never reapest; thou shalt bring in but never carry out [Rashi explains that the son understood this as "You should bring in merchandise and never sell it"]; thou shalt give forth but not bring in [the son understood this as "You should sell but not receive payment - Rashi]; thy permanent house shall be waste and thy temporary dwelling shall be inhabited; thy table shall be confused and thou shalt not see a first year."
When he returned to his father, he said: "Not only did they not bless me, but on the contrary they caused me grief with their words!"
"What did they say to you?" asked his father. He recited the above. "All these are blessings!" exclaimed his father:
"Thou shalt sow and not reap" means (allegorically) that you shall bear children and they shall not die.
"Thou shalt bring in and not give forth" means that you will bring in your house wives for sons, and your male children shall not die, so their wives will not need to leave your house.
"Thou shalt give forth and not bring in" means that you shall have daughters and their husbands shall not die, so that they shall not be compelled to return to your house."
"Thy permanent house shall be ruined and thy temporary dwelling shall be inhabited" means that this world is only a temporary dwelling and the world to come is the real house. As it is said [Psalms 49, 12] "Their inward thought is, that their houses are to be forever". Do not read kirbom (their inward) but kivrom (their graves) - [that is, you should be revived immediately through Techias Hameissim - Rashi].
"Thy table shall be confused" - on account of many chldren.
"And thou shalt not see a first year" means that your wife shall not die, so that you shall not be compelled to marry another." [the first year refers to the first year of marriage in which the chosson is compared to a king - Rashi]
The Maharsha suggests that Rabbi Yonosson and Rabbi Yehuda spoke in a riddle in order to test Rabbi Shimon's son's wit. He also says that the son knew that the rabbis meant to bless him, but he was troubled that he could not figure out the riddle. That is why he told his father: "they caused him grief" rather than "they cursed me", for he was confident that the rabbis would only bless him.
The Rif explains the rabbis' action by suggesting that the rabbis spoke in a riddle knowing that the son would not understand, in order to get the blessing from Rabbi Shimon's mouth, who would surely interpret it as a blessing.
But the Iyun Yaakov asks, how could they have been so sure that Rabbi Shimon would be able to discover the answer to the riddle?
From the Rebbe's Commentaries
The Tzemach Tzedek comments that it makes more sense to interpret the foregoing in a simple way. He explains that because these blessings were so sublime, the rabbis had to conceal them in what appeared to be a curse.
We can understand this in the context of a premise explained in the Tanya (Ch.23): Affliction is really the goodness of the "hidden world"; that's why it manifests itself "like a shade and not as light and revealed goodness". The light is too powerful in its original form and so it must be concealed and "funneled" so that it can be received at a low level. When accepting suffering with joy, one merits that "they who love Him shall be as the sun going forth in its might", which will be in the future to come, when the present sufferings will be seen as visible and manifest goodness just like the uncovered light of the sun.
If, however, these blessings were so high that they had to be disguised, how, then, could Rabbi Shimon bar Yochai interpret them so openly?
There are souls whose task it is to reveal Pnimiyus HaTorah, the hidden inner dimension of the Torah. These souls experience even now an illumination of the future revelations. They are at the level in which they can accept such a sublime light without the need of shade. Therefore, they can recognize the true goodness hidden beneath the veil of the physical world.
Rabbi Shimon bar Yochai, who wrote the Zohar and whose mission it was to reveal Pnimiyus HaTorah, was therefore able to interpret those blessings in a manifest way. He already had an illumination of "the sun going forth in its might", and thus he already saw the reality of the concealed blessings. (This answers the abovementioned question of the Iyun Yaakov).
Revealing the meaning of the blessings is bound up with Pnimiyus HaTorah. Thus, just as Rabbi Shimon bar Yochai revealed Pnimiyus HaTorah to everyone, so he interpreted the blessings for his son, notwithstanding the fact that at the time his son was not yet of high stature. The incomplete status of his son at that time is evident when noting that the Talmud does not refer to him by his name (Rabbi Elazar Berabbi Shimon), but merely as "his son" [See Sanhedrin 41b where the Talmud explains that a student is called simply by his name and not with the title Rabban or Rabbi], and also from the fact that Rabbi Shimon sent him to receive a blessing from Rabbi Yonassan ben Asmai and Rabbi Yehuda ben Gerim
In the time of Moshiach, Hashem's goodness will be revealed. Everyone will see the good that is concealed in anything that may have appeared negative. But from the perspective of Pnimiyus HaTorah we do not have to wait for the World to Come to realize Hashem's infinite and true goodness. We can interpret everything in terms of manifest goodness now.