08 Mar Is Left Right Regarding Hilchos Shabbos?

When one writes with his left hand on Shabbos, he is not committing a transgression. The following question arises; does this apply to all of the melachos on Shabbos or not?

The Mishna in Meseches Shabbos, daf tzadik bais says that one who carries with either hand is chayev as this was the way the children of Kehas carried the mishkan. It would seem that all the other melachos would also be forbidden if one uses his left hand.

One may argue that the fact that we need a special proof regarding carrying; stating that the left hand is forbidden in the same way that the right hand is forbidden, shows that the prohibition only applies to carrying. However, one would be able to do the other melachos with the left hand.

The Ritva writes that the proof from the children of Kehas is showing us that one is committing a transgression even if he carries something on his shoulder. It is poshut that carrying with the left hand is forbidden and we don’t need the posuk stating that that was the way the children of Kehas carried the mishkan. This would seem to say that all melachos would be treated the same way whether it is done with the right hand or the left hand.

The Tiferes Yisrael explains the reason why writing is an exception to the rule mentioned above. Writing is an exact melacha and one cannot write as well with his left hand as he could with his right hand. Therefore, any melacha that requires precision would be permitted when done with the other hand. In a case where one cannot completely finish a bris milah on Shabbos, if it were completed with the left hand, no transgression would be violated.

The question arises; would one be allowed to erase with his left hand or not? The Avnei Nezer writes that one would be chayev in such a case, whereas the Shailos U’teshuvos Z’kan Aharon says that the Elya Rabba says it is permitted. We could reconcile these opinions by saying that it would depend upon whether the erasing is required for one word among other words which would require precision and therefore the left hand is not as precise as the right. In such a case it would be allowed, whereas if the erasing is removing everything on the page and no precision is needed, then the halacha would be the same for the left hand and the right hand and one would be chayev.