Maintaining A Library
‘He Shall Write A Sefer Torah’
(Sanhedrin 21b)
The mishnah on our daf states that a Jewish king is obligated to write a Sefer Torah, based on Devarim 17:18: “… he shall write for himself two copies of this Torah in a book.” Rava rules that every Jew is obligated to write one Sefer Torah (even if he inherited one from his father), while a king must write two sifrei Torah.
Study It Day And Night
The Rambam writes that a king must write two sifrei Torah so that he can constantly occupy himself with studying Torah and the needs of the people (Hilchos Melachim 3:5).
He also writes that if a regular Jew cannot write a Sefer Torah himself, he may commission someone else to write one for him (Hilchos Sefer Torah 7:11).
To Donate Or Not
There is a dispute as to whether one who writes a sefer Torah and donates it to a synagogue or yeshiva is considered to have fulfilled his obligation. Toras Chaim maintains that the essence of the mitzvah is owning a Sefer Torah. Therefore, a person who wrote a Sefer Torah and donated it has not fulfilled the mitzvah. If he wishes to give his Sefer Torah to a shul for the public to use, he must loan it, not give it as a gift.
Pardes Dovid (Parshas Ki Tetze, p. 198, cited by Pischei Teshuva, Yoreh Deah 74:4), on the other hand, notes that it is a common practice to write a Sefer Torah and donate it for public use. Evidently, then, one fulfills the mitzvah by writing (or commissioning) a Sefer Torah even if he later donates it.
It is important to note that the Rambam (Hilchos Sefer Torah, ibid.) maintains that even writing (or commissioning) one letter in a Sefer Torah (as is customary today) is sufficient to fulfill the mitzvah.
The Real Purpose
The Rosh (Menachos, Halachos Ketinos, 1) maintains that the essence of the mitzvah is studying from the Sefer Torah. Therefore, today, when most Torah study is done with printed books – as opposed to Torah scrolls – we are obligated to buy sefarim to fulfill this mitzvah.