Siman 39

Tefillin written by a slave or a woman, or a minor even if he has reached the age of chinuch, or even if he has reached the age of years but has not brought signs [of puberty], or a Kutite, or a transgressor of the entire Torah, or an idolater, or one who desecrates Shabbat; or even a transgressor of a single transgression, provided he does so provocatively and even regarding a rabbinic law; or an informer to an oppressor—all of these are invalid. For it is written: "And you shall bind [...] and you shall write," anyone who is included in binding and believes in this is included in writing. And anyone who is not included in binding, such as a woman, a slave, a minor, a deaf-mute, and a deranged person, or does not believe in it like all those we have enumerated—is not included in writing. And a minor, as long as it has not been clarified that he brought two hairs—is invalid, even if he reached the total of his years. For regarding a Torah law we do not say there is a presumption that he brought signs (Magen Avraham subsection 1). And it appears to me that a transgressor regarding tefillin alone, even if it is not provocatively—is invalid. And even though regarding shechitah he is valid—that is when another checks the knife for him, as I wrote in Yoreh Deah siman 2. And if so, regarding tefillin he is not trusted to say that he wrote them according to the halachah, since there is exertion involved in this. And there is one who says that for appetite—he is valid, for he is called "subject to binding," just as in shechitah he is "subject to slaughtering" (Magen Avraham subsection 3). And I wonder: for granted that he is subject to binding, does he not refuse to exert himself? And this is similar to shechitah when an Israelite does not check the knife, for it is forbidden to eat from his slaughtering. And one whose left hand was severed—is valid for writing, for he is "subject to binding" but merely has nothing upon which to bind. (Ibid. subsection 5. And see Taz subsection 1 what he wrote as a reason regarding an informer. And be precise and you will find it easy.)

And all of these, just as they are disqualified for the writing of the parashiyot, so too they are disqualified for the making of the battim and the straps and for their sewing. However, for the tanning—they are fit. And so too if they scraped between letter and letter—we are not concerned about this. And so too for the sewing of a Sefer Torah, there are those who permit (ibid. subsection 6). And see in Yoreh Deah siman 278, section 11, where we brought one who forbids the sewing of women, and we explained there to permit it. And according to what we explained there, also in the sewing and in the straps they are fit. And only in the battim are they disqualified, because they contain the shin, which is like writing, see there.

A convert (in ancient times) who returned to his religion due to fear, the Rosh and the Tur and the Shulchan Aruch ruled that he is fit to write. However, from Tosafot Gittin (45b) it does not appear so, and likewise the Rif and the Rambam did not cite this. Therefore, one should not be lenient (ibid. subsection 7). Tefillin that were written by a min—they shall be burned. And some say they shall be hidden away. And those written by a Kutite—the law is also thus. Tefillin that were found in the hand of a min, and it is not known who wrote them—they shall be hidden away. And if they were found in the hand of an idolater—they are fit, for certainly an Israelite wrote them, as they are not proficient in writing. And a mamzer—is fit to write tefillin. And see in Yoreh Deah siman 281 (see Magen Avraham subsection 9).

One may not purchase sefarim, tefillin, and mezuzot from an idolater for much more than their value for the sake of the repair of the world, so that they do not habituate them to steal and rob. However, to add a small amount over their value is permitted. And it is a mitzvah to redeem them from their hand. And tefillin are not purchased except from an expert sofer who is proficient in the deficient and full spellings, and proficient in the halachot of tefillin. And if he purchased from one who is not an expert, he must examine them. And since he examines and finds them to have been written with the deficient and full spellings according to the law, we say that certainly he was also proficient in the rest of the laws. And it appears to me that if he found the lines were not aligned, according to what has been explained in siman 35, their status is weakened. And one does not rely upon them unless it is clarified that an expert wrote them, for although this is not a disqualification post facto, nevertheless, it is a flaw.

Our sages, of blessed memory, said (Eruvin 97a) that if one took many pairs of tefillin from someone who is not known to be an expert—he checks three tefillin from them, two of the hand and one of the head, or two of the head and one of the hand. If he found them to be kosher—all of them are established as kosher, and the rest do not require checking. This is when it is recognizable that all of them are the handwriting of one scribe—his writing is established as kosher. But if they were in several bundles where it is recognizable that they are from several scribes—he checks from each bundle accordingly, two of the hand and one of the head or vice versa. And one who sells tefillin and says "they belonged to a great man"—he is believed, for a single witness is believed in matters of prohibitions, and they do not require checking. This is on the condition that this man is established in kashrut.

Tefillin that have been established as kosher do not ever require examination. But if one only dons them occasionally, they require examination twice in a seven-year period, for we fear perhaps they have rotted. And the same law applies if they came into contact with water—they require examination. However, if he does not have someone who is able to sew them afterward, it is better not to open them to examine, and he should don them thus without examination. And know that this is according to the law. But in our times, it is known that our ink, over the course of several years, peels off from the parchment. Therefore, nowadays it seems to me that according to the law one must examine them at some point in time, and so one should practice.