Hak Tochot

Source

1. The Gemara Gittin differentiates between two types or carving: חק תוכות, carving the centers of the letters and their sides, and חק יריכות, carving of the legs of the letters themselves.

Definition

1. There are many letters of the Aleph Bet which contain three walls. The space between these walls is called the “inside” –“תוך” (singular of תוכות, Tochot). For example, the letters ב,ה,ח,ט,כ,מ,ס and ת clearly have an inside surrounded by three walls.
2. חק תוכות literally means that one may not erase the middle of a letter and the ink around it that's not erased will form the letter itself. This rule of חק תוכות applies to all the letters, even part of a letter, and is not limited to letters that actually contain an inside.
3. If the letter is formed by carving, removing, or erasing excess ink that surrounds it, it is considered Hak Tochot and is Passul.

Halacha

1. If a drop of ink falls on a letter making the letter unrecognizable, the drop may not be removed because it is considered Hak Tochot.
2. Similarly, if a letter is written incorrectly, if the mistake makes the letter unrecognizable, ink may not be removed (erased) to correct the mistake.

Application

1. The following are several examples in which the Issur of Hak Tochot applies:
   1. If a drop of ink falls inside the letter Dalet, ד, making it look like a He, ה, removing the drop is Assur because it is Hak Tochot. The Dalet was formed (From a He to a Dalet) by removing the drop of ink.
   2. If a Sofer accidentally adds an Ekev, heel, to the letter Caph, כ, making it look like the letter Bet, ב, it is Assur to remove the Ekev, because it is Hak Tochot.
   3. If a drop of ink Falls inside the letter Caph, כ, making it look like the letter Pe, פ, removing the drop is Assur because it is Hak Tochot.
   4. If a drop of ink falls on the letter Mem, מ, making it look like the letter Mem Sofit (Mem in its Final letter form; in the end of the word),ם,removing the drop is Assur because it is Hak Tochot.

Avoiding Hak Tochot

1. If any such mistakes should happen, rendering the letter unrecognizable, what should the Sofer do? The Sofer must remove the drop of ink as well as a part of the letter so the letter remains unrecognizable. Then he must rewrite that part of the letter that was removed. In this way, the letter is completed by writing it and not by removing the ink around it, Hak Tochot.
   1. For example: If a drop of ink falls on the letter Mem, מ, making it look like the letter Mem Sofit , ם, recreating the Mem by simply removing the drop is Assur because it is Hak Tochot. However, the Sofer may erase the enire leg of the Mem, leaving only the shape of a Nun, נ, and then rewrite the leg. In this way the letter is completed by writing and not by erasing the ink around it.