Rashi explains that the men came to study; the women came to hear words of Torah; the children came to give reward to those who brought them. Nachlas Tzvi cites Horav Shraga Moshe Kalmenovitz, zl, who derives a significant lesson from the fact that the parents received reward for bringing their infants to the Hakhel gathering. After all, if the parents were obligated to come, who would be taking care of their children? If the Torah demands that the parents attend, it should take into consideration that there is a family at home. For this reason, the Torah provided a special reward for those who brought their young children. The parents obviously had no other alternative but to bring them. Yet, the Torah rewarded them for what they were compelled to do. That is the beauty of the Torah.
Horav Moshe Wolfson, Shlita, offers a number of alternative approaches towards answering the question. His first reason is a practical one. Over a year had passed during which Klal Yisrael had not worked in their fields. It was the eighth year in the Shemitah cycle, the first year following the Shemitah. The people were about to plow and plant for the next harvest. They needed Hashem’s blessing that it would be a successful harvest. They all gathered in Yerushalayim on Succos to pray for water for the coming year. Chazal teach us that the greatest merit for effecting Hashem’s blessing of rain is tzedakah and acts of loving kindness. Indeed, when Chazal turned to Abba Chilkiya to pray for rain, both he and his wife prayed. The rain clouds appeared in his wife’s side of the room, where she stood in supplication. This occurred because she was at home and, thus, had greater opportunity to help the poor.
When all of Klal Yisrael congregated in Yerushalayim for the festival of Succos and the Hakhel experience, they obviously needed places to stay. The open-hearted attitude of the city’s citizens and their warm welcome to the guests made this experience very amenable. The added guests placed the primary burden upon the women who provided the care for the visitors. There are two ways to host guests: One can wait until the visitor knocks on the door and then welcome him. This is referred to as hachnosas orchim, welcoming guests to one’s home. There is an even higher level of greeting visitors: Seeking guests and then bringing them home. This is called havoas orchim. Hashem Yisborach knew what is required to welcome guests to Yerushalayim. He also distinguished between those that welcomed guests and those that sought them out to bring them home. He wanted to give an extra reward to those who brought the guests to their home, the “mevieiham”. He did this by instructing the Jews to bring along their infants, thereby increasing the effort for those special women who brought guests to their homes, thus increasing their reward.
In his last two reasons, Horav Wolfson gives essentially the same response, but as the result of two separate reasons. First, we must keep in mind that the people had to expend limited physical effort during the Shemitah year. They were not permitted to work their fields. In an agricultural community, this is the primary occupation. During Shemitah, they had an entire year to devote themselves entirely to spiritual pursuits, to study Torah, to pray longer and with more devotion, to give more of themselves to spiritual devotion and reflection. The infants that these people brought for the Hakhel experience were the “products” of the Shemitah year, a year during which the parents’ spiritual level soared. These special children indeed engendered a great zechus, merit, for Klal Yisrael, their “mevieiham,” who brought them into the world. Their presence was as unique as they were.
Last, Horav Wolfson explains that while bitachon, trust in the Almighty, is a necessary component in every material endeavor, it is especially necessary in order to maintain one’s spiritual plateau while he is confronting the challenges of the material/physical dimension. One needs bitachon in order to pray with devotion, so that he does not rush through the davening because he might be late for a business deal. It is especially difficult to take time off from one’s financial pursuits to study Torah during the workday. Maintaining a high level of integrity also demands bitachon, for one to believe that he will earn what he is destined to earn regardless of the time and effort he expends in pursuing his goal.
The Shemitah year is the ultimate test of one’s trust in Hashem. It truly distinguishes between those that have bitachon and those that are lacking in this pivotal attribute. What would the average citizen of the world do when confronted with such a challenge to his faith? He would be frugal and meticulous in everything he spends. He would do everything not to burden his finances in any way. Indeed, having and raising children would be the first area of abstinence! Not so the observant Jew whose trust in the Almighty is unequivocal. He proceeds with life as usual, trusting Hashem to provide for him and his family while he carries out Hashem’s mitzvos. The children that he brings into this world during the Shemitah year are living testimony of his unwavering bitachon in the Almighty. Hashem, therefore, instructs him to take these children to Yerushalayim so that he and all those others who brought these children into the world during the year of Shemitah will receive their extra reward that they truly deserve.