Following this line of reasoning, we will now explain the profound wisdom of Avraham Avinu. He made a lavish feast for all the big people such as Og and the other giants “on the day Yitzchak was weaned”—the day he placed Yitzchak in his own crib. He had been commanded to circumcise Yitzchak when he was eight days old. He saw that HKB”H modified the natural order of the world. Until now, everybody was born fully grown with knowledge. This enabled them to fetch whatever their mothers asked them to fetch on the very day they were born. This all changed with the birth of Yitzchak.
Avraham sought to understand why HKB”H altered nature specifically with Yitzchak. He realized that Yitzchak was the first human being born as a Jew. According to two different opinions in the Midrash (ibid. 64, 4), Avraham Avinu did not recognize the presence of his Creator until he was either three years old or forty-eight years old. In other words, the bloodline of those born as Jews began with Yitzchak Avinu. Therefore, Avraham was instructed to circumcise Yitzchak when he was but eight days old—still small and lacking knowledge. This was meant to establish a fundamental principle and precedent for all future generations of Jews. Chinuch must be initiated when our children are very young; we must not wait until they are knowledgeable. For, then chinuch is more difficult, since they already have minds of their own.
To publicize and spread the emunah in Hashem throughout the world, Avraham Avinu devised a clever plan on the day Yitzchak was weaned from his mother’s milk. He placed Yitzchak in a crib surrounded by guardrails to protect his son and prevent him from falling out. This was a magnificent symbolic gesture emphasizing the need to also protect a child spiritually even while it is still in a baby crib. A child should not be allowed to do whatever it wants to do with total disregard for Torah and mitzvos. It was for this reason that Avraham threw a lavish party for all the giants of the world on the day Yitzchak was moved to a baby cradle. He wished to demonstrate to them that the proper and best way to serve Hashem is to initiate a child’s chinuch at a very young age, in keeping with the passuk: "חנוך לנער על פי דרכו גם כי יזקין לא יסור ממנו".
This is also why the Midrash mentions rocking the cradle: עריסה תחלה אלא בביתו של אברהם אבינו""לא נדנדה. The purpose of rocking a cradle is to calm an infant down when it is uncomfortable or upset. In keeping with this discussion, this represents a symbolic gesture to educate a child and calm him down when he is faced with the yetzer hara. He must learn the importance of setting up strong, firm guardrails, and establishing boundaries, so that he will now fall into the traps of the yetzer hara.
It is worthwhile interjecting what the Avodas Yisrael writes regarding a passuk in parshas Shelach (Bamidbar 15, 20): "ראשית עריסותיכם חלה תרימו תרומה"—the beginning of your kneading you shall set aside a loaf as a portion. He interprets this passuk allegorically. A person should not think to himself: “I am still quite young and there is plenty of time to do all of these things. When I grow old, I will resume serving the Almighty by elevating the sparks of kedushah. For the time being, it is written (Koheles 11, 9): ‘Rejoice young man in your childhood.’” To which, the Torah teaches us here that this is not the proper attitude. Rather: “The beginning of your kneading you shall set aside a loaf as a portion”—the essence of one’s service to Hashem is in one’s childhood and adolescence, when a person is still full of vim and vigor. This initial, youthful energy should be dedicated and sanctified.
Based on what we have learned, we can embellish this thought. We can suggest that this passuk alludes to the obligation of chinuch incumbent on parents. For, the word "עריסותיכם" can refer to a crib, the bed of an infant. We find this term used in the Gemara in this context (Berachos 47b): "קטן המוטל בעריסה"—an infant lying in a crib. Thus, we can interpret the passuk as follows: "ראשית עריסותיכם"—when children are still confined to a crib; "חלה תרימו תרומה"—it is already the appropriate time to elevate them by educating them to be a servant of Hashem. They should become accustomed to follow in the ways of Avraham Avinu, who threw a lavish party on the day that Yitzchak was placed in a cradle to symbolize the importance of initiating the process of chinuch as early as possible, even in infancy.
This explains beautifully what Rabban Yochanan ben Zakai attests regarding his disciple Rabbi Yehoshua ben Chananyah (Avos 2, 10): "אשרי יולדתו"—praiseworthy is she who bore him. Based on the Yerushalmi (Yevamos 1, 6), the Bartenura explains that when the sages came to Rabbi Dosa ben Hyrkanos, he saw Rabbi Yehoshua and exclaimed: “I recall that his mother would walk his cradle to the Beis Kenesses, so that his ears would be immersed in words of Torah.” Based on this discussion, we can suggest that his mother was emulating Avraham Avinu, who placed Yitzchak in a crib to demonstrate the need to begin chinuch at an early age.
