The Torah insists that nothing may be added to it and nothing must be taken away (Deuteronomy 4:2). That nothing ought to be taken away is clear. That would be rejecting the integrity of God’s word. But why not add to the Torah? It is this question that is addressed by the Maggid of Dubno, Rabbi Jacob Wolf Kranz (1740–1804) in his book Ohel Ya’akov.
There once was a man who regularly borrowed items from his neighbor. Every time he borrowed something he returned two of the items borrowed. Had he borrowed a spoon, he would return two spoons. Had he borrowed a dish, he would return two dishes. The generous neighbor who had been lending out his goods was dumbfounded. He asked the borrower why he always took one but returned two. The borrower explained that it was quite simple. The item lent him became pregnant and gave birth to another, so he felt obligated to return two. The lender saw an advantage here so he gladly lent out any item the borrower wanted.
One day, the borrower asked for the elaborate and costly silver candelabrum. He was arranging for a banquet in his home and felt that the candelabrum would be a fine adornment. The neighbor happily lent him the candelabrum with the gleeful expectation that he would be enriched with the return of two. But that was not to be. The next day, borrower did not appear. The neighbor went to the borrower asking for the candelabrum in return. But the borrower told him that he had bad news to report. The candelabrum he borrowed took sick and died. There was nothing for him to return. The owner of the candelabrum was irate. “Who ever heard of a a candelabrum dying!?” The borrower would have none of it. “Who ever heard of spoons and dishes giving birth?” If the lender was willing to accept the fact that inanimate objects can give birth, he should also be willing to accept that they can die.”
Thus, the Dubno Maggid concluded, the same applies to commandments. A person who adds to the commandments, that is, believes that they can give birth, will ineluctably believe that commandments can die. Therefore, the Torah warns against additions as much as substractions.