Commentary for Kiddushin 59:3
עד היכן חייב אדם ללמד את בנו תורה אמר רב יהודה אמר שמואל כגון זבולון בן דן שלימדו אבי אביו מקרא ומשנה ותלמוד הלכות ואגדות מיתיבי למדו מקרא אין מלמדו משנה ואמר רבא מקרא זו תורה
To what extent is a man obliged to teach his son Torah? - Said Rab Judah in Samuel's name: E.g. , Zebulun, the son of Dan, whom his grandfather taught Mikra [Scripture], Mishnah, Talmud,<span class="x" onmousemove="('comment',' The discussion of the MISHNAH:');"><sup>4</sup></span> halachoth and aggadoth.<span class="x" onmousemove="('comment',' V. Glos.');"><sup>5</sup></span> An objection is raised: If he [his father] taught him Mikra, he need not teach him Mishnah; whereon Raba said: Mikra means Torah?<span class="x" onmousemove="('comment',' The Pentateuch. In the earliest terminology we find Torah and Mikra opposed, the former referring to the Pentateuch and the latter to the other Books of the Bible (v. J.E., 'Bible, Canon', III, 142) ; here they are identified.');"><sup>6</sup></span> - Like Zebulun B'Dan, yet not altogether so.
Daf Shevui to Kiddushin
The answer is brought from the case of someone named Zevulun son of Dan, who Rashi said was a contemporary of Shmuel’s. Zevulun learned from his grandfather basically all of the fields of Torah.
Daf Shevui to Kiddushin
The resolution is that the example of Zevulun b. Dan was come to show that even a grandfather is obligated to teach his grandson Torah. But fathers (and grandfathers) are obligated to teach only Mikra, not all the fields.