Checking sta”m by a computer

By Rabbi Chaim Chazzan


Is one obligated to have one’s sta”m (– Sefer Torah, teffillin and mezuzos) checked for their kashrus by a computer?


All contemporary poskim concur that a computer cannot replace the obligation of checking sta”m by a person. However, since even after the sta”m has been checked by a person, the computer often finds missing words, letters and incorrectly formed letters, there are poskim who include a computer check in the general halachic principle “kol ma de’efshar livrury mevarerinon” – when the concern for psul is common we ought not to rely on a chazaka for anything that is possible for us to investigate. Hence, they hold that with the technological advances of today a computer check is obligatory.

Checking sta”m with a computer cannot be compared to checking vegetables for bugs with a microscope, or checking if tefillin are square with a modern mechanical device, which are both not required by halacha. Halacha is only concerned with phenomena observable to the naked eye; therefore anything not observable would not be included in the prohibition or obligation. However a mistake in a sefer Torah is readily observable and hence renders the sefer Torah posul. All the computer is doing is exposing the location of a psul.

Other poskim however, are of the opinion that although it is commendable to check sta”m with a computer, there is no obligation to do so, and there are surely no grounds to disqualify sta”m which was not checked by a computer.

Another possible issue may be the prohibition to erase Hashem’s name caused by scanning the sta”m, however poskim are not concerned with erasing Hashem’s name on a computer screen.

שו”ת שבט הלוי ח”ז סי’ ב,ג,ד. תשובות והנהגות ח”ב סי’ צט. קנין תורה ח”ה סי’ קו. משנה הלכות חי”א סי’ קיד, קטו.

Reprinted with permission from  Lmaan Yishmeu – a project of Mercaz Anash. To see more articles visit


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