Mezuzah, Tefillin and Torah
The Scribal Art
Oochsavtom means "and you shall write them" ("on the doorposts of your house..."). The Sages explain that this word can be read as two words: Oochsav tom, "a perfect script". The special script in which the mezuzah, like tefillin and a sefer Torah, is written, has been very precisely defined by the Sages. In the halachic codes the exact form of each letter, from alef to sof, is clearly described. Each letter must be written perfectly in accordance with these laws, for the slightest flaw can render the whole mezuzah or tefillin posul. The letters may not touch each other, but should be separated by at least a hairbreadth space. The space between two words should be the size of a letter yud. If two words are written so closely together that a child learning to read thinks they are one word, the mezuzahs or tefillin are posul. This is also the case if a large space in the middle of a word makes it seem like two words.
The Correct Order ‘כסדרן’
An important condition which mezuzahs or tefillin must fulfill is that is must be written in the correct order. This means that a mistake found in mezuzahs or tefillin often cannot be put right. The corrected letter would be written after the subsequent text of the mezuzah or tefillin, and would not be in correct order.
If the mistake is found in the last line or two, these words can be erased and then rewritten correctly. The correct order has been preserved. But it is forbidden to erase the Name of G-d. This occurs in the penultimate line, so if any mistake is found in an earlier line, the mezuzahs or tefillin are irredeemably posul and must be buried. Hours of work by the Sofer and parchment-maker have unfortunately gone to waste.
Because of this stringent stipulation, the Sofer is always very careful before writing the Name of G-d and meticulously checks through everything he has written earlier before writing it.
The law of "the correct order" does not apply to a sefer Torah, which therefore can be corrected. In this respect that law concerning writing mezuzahs or tefillin are stricter than that concerning a sefer Torah.
Writing by Erasing ‘ חק תוכות’
The halacha requires that each letter be written perfectly. It must not be written by erasing, For example, if, in error, the Sofer wrote beis instead of kof, he might feel that by erasing the foot of the beis a kof would remain. This, however, is writing by erasing and the mezuzahs or tefillin are therefore posul. The same would apply to an attempt to change a daled into a reysh.
This law also applies if a drop of ink splashes onto a letter. Even if the ink can easily be cleaned away leaving the letter intact the law of writing by erasing may have been contravened.
It is clear from these laws that even if mezuzahs or tefillin appear all right, it may actually be posul. It is essential to buy one’s mezuzahs or tefillin from a reliable source. A reliable source is best defined, that the seller knows who is the scribe and that the scribe has been certified. Scribes that are not tested and certified may not be aware of the many laws pertaining to mezuzahs or tefillin. As a result, what you’re buying may be 100% posul even if it looks kosher.
What is the purpose for the crowns ‘Tagim’ on some of the letters?
Are mezuzahs or tefillin kosher without those crowns?
The seven letters, shin, ayin, tess, nun, zayin, gimmel, tzaddy, must have tagim (crowns). The crown is made of three little lines, each one often shaped like the letter zayin, extending from the top of the letter. The tagim must be clearly written and may not touch any other letter. Some other letters can also take tagim, but the most important are the seven mentioned above.
The Talmud tells us that when Moses was on Mount Sinai "he found the Holy One binding crowns for the letters". He saw how the great Rabbi of the Mishnah would reveal the profound secrets of the tagim after many generations,, Rabbi Akiva. If mezuzahs or tefillin do not have tagim they can be added later (because the basic form of the letter is already present). An unfortunate fact is that many mezuzahs or tefillin are sold without any tagim, or they may have only a few. Those who write and sell such mezuzahs or tefillin plead that because they are so small there is not enough room to write the tagim. This is like constructing a car without a gas tank in order to save space! If the scribes of today do not have the skill to write tagim in a small mezuzah then it is up to us to ask them to write one of a slightly larger size.