One of the many mitzvos in this week’s double portion of Acharei Mos and Kedoshim is the mitzvah of Orlah: “When you come into the land and you plant any fruit bearing tree and you shall stay away from its fruits for the first three years, you shall stay away from them and not eat from it. And on the fourth year all the fruit shall be holy, praises to Hashem. And on the fifth year you shall eat from its fruit to add for you its produce, I am Hashem your G-D” (Vayikra 19:23-25).
asks: why can we not eat from any tree the first three years of its existence, and on its fourth year the fruit is treated like maaser sheni (only being eaten in Yerushalayim while praising Hashem, as the Rashbam
points out). “The reason for this is to honor Hashem from the first produce of the fruit of the tree and produce of the vine and not to eat from them until all the fruit of one year is brought as praises to Hashem. Behold, fruit in general is not able to be brought within the first three years before the honorable Hashem since they are very little and the tree does not give off into the fruit its good taste or smell within the first three years. A good portion of trees don’t produce fruit at all with in the first three years until year four. For this reason by all of them we wait and not taste any of them until it is brought from what was planted all its first good fruit as holy before Hashem, and there they shall eat and praise Hashem. This mitzvah is similar to the mitzvah of bikkurim."
The Chizkuni writes something very similar to the Ramban, but with a slight twist, which is worth highlighting: “For the first three years you should stay away from them because it is not proper manners that one should benefit until they bring it as an offering before Hashem for really it is befitting to bring the first of all the produce but the first three years after planting a tree does not produce anything nice and worth accepting to make from it an offering to Hashem since the tree hasn’t fully taken root and settled into the ground.” (Click here for Hebrew text.)
According to the Chizkuni it is not just a lack of respect or honor to eat from the first fruits produced from a tree, it is a lack of manners on behalf of the tree owner. There seems to be a character flaw, a basic lack of common courtesy shown, by one who eats fruit from a tree within the first three years of planting; not just a lack of honor and respect towards Hashem.
What seems to be perplexing is: what is the big deal about eating these fruits? Anyways, they are inappropriate to be brought before Hashem since they are inferior and only into the fourth year is the fruit ready to be brought before Hashem. It definitely makes sense to bring the best fruit before Hashem in His honor and it would be a tremendous disrespect to eat them “not in front of Him,” without praising him. But why is it a lack of courtesy to eat any fruit which is undeserving to be brought before Hashem; they are anyways unbefitting?
It would seem that it is common courtesy, or basic manners, to give first to someone of higher and more important stature before taking for yourself; it just happens to be disrespectful to give inferior produce, so one must wait until they are important enough to be worth giving. But anything beforehand is untouchable because you are then placing the more important person, in this case Hashem, second - and that is a basic lack of derech eretz, common courtesy.