The melachot of kotev and mochek, writing and erasing, raise many questions which bear significant practical implications. One such question flows from a seeming omission of the Talmud: The Talmud fails to address an instance in which a person causes the result of ketiva or mechika to come about, either without performing any act of writing or erasing whatsoever, or by writing in a fashion that in no way resembles the classic acts of writing and erasing. One practical example of this would be cutting the letters made with icing on a cake. What is the halakha in such cases?
Perhaps the seminal source regarding this subject is the Magen Avraham’s commentary on Shulchan Arukh. The Magen Avraham1 rules that one may not attach or detach silver letters from the shirt to which they are attached, for doing so would be a violation of the melachot of kotev and mochek. Others, such as R. Barukh ha-Levi Epstein, author of the Arukh ha-Shulchan,2 disagree, claiming that attaching and detaching letters does not fall under the rubric of halakhic writing.
In fact, it is possible to trace this question to the commentary of the Mordekhai, a medieval authority, whose collection of the rulings of German and French scholars appears in the back of the Talmud. The Mordekhai3 quotes the Maharam mei-Rutenberg, who ruled that one may not slice letters that appear on a cake, on the basis of the melacha of mochek. The Rama quotes this pesak of the Mordekhai in Shulchan Arukh,4 and the Gra5 and Magen Avraham6 similarly uphold the ruling of the Maharam. The Magen Avraham, however, does raise the possibility that if the letters are part of the cake itself – as opposed to when they are written in icing, which is generally added later on – there is more room to rule leniently.
Many acharonim question the ruling of the Mordekhai entirely,7 for a wide range of reasons. One of the considerations that is raised revisits the question debated by the Magen Avraham and Arukh ha-Shulchan: Here, the act of “erasing” the letters on the cake seemingly does not resemble the normal act of erasing. They wonder, does this mean that one does not violate the melacha of mochek in such a case?
Practically speaking, the Mishneh Berurah8 rules stringently like the Mordekhai, but is willing to rely on the Magen Avraham to be lenient if the letters are written on the cake itself.9 Furthermore, the Mishneh Berurah is lenient if one “cuts” the letters with his teeth, as part of the process of eating the cake. Modern-day poskim generally follow these rulings of the Mishneh Berurah.10
It should be further noted that most poskim hold that one should avoid cutting pictures as well11 , based on the Yerushalmi12 and Rambam13 who apply the melacha of kotev to drawing pictures, as well. Finally, it would seem that one may cut in between the letters, as long as the shape of each individual letter remains intact.14
1 Orach Chaim 340:s”k 10
2 ibid., s”k 33
3 Masekhet Shabat, ot 369
4 Orach Chaim 340:3
5 ibid., s.v. asur
6 ibid., s”k 6
7 See Taz, Dagul mei-Revava, and Peri Megadim ad loc.
8 ibid, s”k 15
9 This case is to be treated more leniently, explains the Mishnah Berurah, because the letters are not halakhically defined as a ketiva, but merely as part of the cake. Letters only constitute halakhic writing, according to this approach, if they are originally a separate entity, and are later appended onto the cake.
10 Shemirat Shabat ke-Hilchata 11:7; Rabbi Ribiat’s The 39 Melochos vol. 3, pg. 987.
11 ibid.
12 Shabat 7:2
13 Hilchot Shabat 11:17
14 The 39 Melochos, pg. 988