bet sefer means the house of the teacher of the Torah. To study the Torah is called talmud torah;
The father was traditionally the sole teacher of his children in Jewish history (Deut. xi. 19). The institution known as the "be rav" or "bet rabban" (house of the teacher), or as the "be safra" or "bet sefer" (house of the book), is said to have been originated by Ezra' and his Great Assembly, who provided a public school in Jerusalem to secure the education of fatherless boys of the age of sixteen years and upward. But the school system did not develop till Joshua ben Gamla the high priest caused public schools to be opened in every town and hamlet for all children above six or seven years of age.
- Scroll of Torah