It takes a professional scriber (Sofer STAM) almost a year to write on parchment some quarter of a million of letters. The Sofer STAM is not allowed to write from the memory, for it will imply disrespect to the authority of previous generations. Writing process is a holy work, above all it is a demonstration of the scribe reverence to the tradition and the expression of his desire to sanctify the world with bringing down of the teachings of G-d. Therefore the scribe has to look into the text of a Chumash for each next letter, concentrating himself on the holiness and significance of each of the letters of the Torah Scroll.

     Oral tradition says, that all the letters of the Torah comprise one integral Name of G-d, and every letter is the letter of His Name. Therefore the writing of a Torah Scroll requires care and attention to ensure accuracy. Should but one letter be missing or one extra letter be added, the text will not be graced with the Kedushat Sefer Torah (holiness of the Torah Scroll). Talmud brings down the following dialogue to support this understanding:

     When R. Meir became a student of R. Yishmael, the latter asked him, "My son, what is your profession?" R. Meir replied, "I am a scribe." To this R. Yishmael remarked, "My son, be scrupulous in your profession, for it is a heavenly pursuit, and should you delete one letter or add one letter, such effort is tantamount to destroying the entire world" (Eruvin 13a).

     However, before a Sofer STAM starts writing, he has in fact to write and delete a whole groups of letters. This dates back to the tradition of remembering and blotting the memory of Amalek, the ancient tribe that did not allow the Jews coming out of the desert to pass through their territory. Instead, they unleashed the war against the Jews, exhausted by years and years of life in the desert. Torah instructs that we have "to blot the memory of Amalek from ounder the heaven - and not to forget" (Devarim, 15:19). Thus, the sofer literally implements this commandment written in the Torah: on a special sheet of their parchment he writes down the name of Amalek and crosses it out. Now evil is blotted out, the scribe may get down to his holy work.