בראשית פרק כד, א וְאַבְ רָ הָם זָקֵן בָא בַיָמִּ ים
מסכת יומא כח/ב א "ר חמא בר' חנינא מימיהן של אבותינו לא פרשה ישיבה מהם אברהם אבינו זקן ויושב בישיבה שנאמר ואברהם זקן בא בימים
Similarly, Chazal explain regarding Yitzchak, Yaacov, and the elders of the generation of the desert, that they learned Torah and were all called “elders” (זקן). This requires some explanation. All elderly people acquire knowledge through their life experiences. However, some young people also acquire knowledge, and it is not limited to an elderly person that gains through life experiences. Therefore, Torah calls such a person, a זקן no matter their age, since they acquires knowledge and spread Torah.
In addition, Torah literature tells of yeshivos and spreading Torah done by Avrohom, Yitzchak, Yaacov, and others, prior to the Giving of the Torah. Originally, in the days of Enosh, people erred and began to give honor to G-d by also honoring the creations in the heavens (stars, planets, sun). Thereafter, the people confused the honor, and began to make statues, monuments, etc. and considered these items as having G-dly powers. This continued until Avrohom when he understood that only One G-d created everything, without anything else. Avrohom began to teach and spread the knowledge of the One G-d, and gathered thousands to return to the correct path. He wrote many books and taught them to the people that came to him. And after him Yitzchak and Yaacov continued this service. They appointed Levi to head the “school”, who in turn taught the entire tribe of Leviim and the Elders. And this is the concept that yeshivos and spreading Torah never stopped in regards to the Avos.
