Reference for Kiddushin 59:7
אמר ריב"ל כל המלמד את בן בנו תורה מעלה עליו הכתוב כאילו קבלה מהר סיני שנאמר והודעתם לבניך ולבני בניך וסמיך ליה יום אשר עמדת לפני ה' אלהיך בחורב (דברים ד, י)
R'Joshua B'Levi said: He who teaches his grandson Torah, the Writ regards him as though he had received it [direct] from Mount Sinai, for it is said; 'and thou shalt make them known unto your sons and your sons' sons', which is followed by, that is the day that thou stoodest before the Lord thy God in Horeb.<span class="x" onmousemove="('comment',' Ibid. 10.');"><sup>11</sup></span> R'Hiyya B'Abba found R'Joshua B'Levi wearing a plain cloth upon his head<span class="x" onmousemove="('comment',' But not a sudarium, V. supra p. 142, n. 2,');"><sup>12</sup></span> and taking a child to the synagogue [for study].<span class="x" onmousemove="('comment',' In Talmudic times the teaching took place in the synagogue.');"><sup>13</sup></span> 'What is the meaning of all this? ' he demanded.<span class="x" onmousemove="('comment',' Why was he so hasty to go out as not to don Proper headgear? tmnut');"><sup>14</sup></span>