הלכה אויף זכריה 13:6

Children should be enrolled for instruction at the age of six or seven years, in proportion to the strength of the child and his physique. A child under six years should not be sent to school. The teacher may inflict punishment upon the school children that they may fear him; but he must not smite them with hatred and cruelty; he should, therefore, not strike them with rods or sticks but with a small strap. He should instruct them during the entire day and part of the evening, so that they be brought up to study by day and by night. Children should not stop school at all save on the eves of Sabbaths and holidays, and during holidays. On the Sabbath no new lessons should be given but lessons may be repeated. School children should not be rendered idle even for the sake of building the Holy Temple.²Baba Batra, 21b; Ketubot, 50a; Nedarim, 37a. C. See Ta’anit 3b. G.