Presumably, your question is about how to explain the fact that we spend time raising children that we could instead be devoting to various mitzvot. The fact that all normal Jewish (and non-Jewish) families will continue toiling for their children is a given; you are simply asking how and if this practice is justified. Your question presents a wonderful opportunity to briefly discuss some basic principles of avodat Hashem,[1] before presenting sources and analysis in an attempt to solve the moral mystery you have identified.
HaShem gave us mitzvot, which are the highlights of our life, but our life situations also require that we learn how to incorporate undeniable realities, both mundane and profound, in our existence. HaShem made the world in such a way that we must eat, sleep, go to the bathroom, bathe, etc. These are not mitzvot in the classic sense, but HaShem clearly wants us to partake in these regular, time-consuming routines. These activities are so obviously a part of our lives that they do not need to be commanded in order for us to know that we should partake in them.
Let us illustrate with a famous pasuk, the source of the mitzva to recite Birkat HaMazon: “You shall eat and you shall be satiated, and you shall bless HaShem, your G-d, for the good Land He gave you.”[2] The pasuk contains three verbs that are presented in the same manner of “you shall.” “You shall bless HaShem” is the Biblical source for the mitzva of reciting Birkat HaMazon. Why did Chazal not similarly derive a mitzva to eat and another mitzva to be satiated? The answer is that it is understood that we generally eat food until satiation, because that is normal and necessary for human beings, which HaShem created us to be. If we need confirmation that HaShem wants us to eat normally and not be ascetics who barely eat food, note the p’sukim in the second section of Kri’at Shema,[3] where we are told that when we keep the mitzvot of the Torah, HaShem will bring rain and our crops will grow and be harvested. This section, describing the ideal situation,[4] ends with “you shall eat and be satiated.” Thus, the standard ideal includes ample eating, not abstaining from eating out of asceticism. Accordingly, if one has to choose between eating a full meal or doing a mitzva, he is not normally expected to forgo the meal.[5] Similarly, when one is busy with work, another proper non-mitzva activity, he is generally exempt from involving himself during that time with mitzvot, whether they be learning Torah, visiting the sick, writing a sefer Torah, etc.[6]
We can draw further insight from the Torah perspective on supporting children. A father (not mother) is required Rabbinically – not by Torah law – to support his children when they are young.[7] Before the Rabbis instituted this obligation on the father, did the average father not support his family?! Consider the Torah-derived law[8] that an eved ivri’s[9] master must support his servant’s wife and children. The rationale behind this law clearly seems to be that the father/family breadwinner is at work all day for the master and can no longer support his family. But why should the master be required by Torah law to support them in lieu of the father, when the father himself is only Rabbinically obligated? The answer is that the Torah left it to fathers to support their families because they are normal human fathers, and the Torah trusted that as a rule, they would do so without a specific Torah mandate. Similarly, the Torah expects a mother, who is technically not obligated to support her children, to provide food for them if they do not have a father doing so. In the animal kingdom, parents do this based on instinct; among humans, this instinct is augmented by basic G-d-given morality. The Torah, for reasons I cannot identify with precision but with which my intuition identifies, preferred not to formally legislate such positive behavior.
The Torah expects parents to be busy with their children’s various needs, which are harder to delay than most of one’s personal needs. Attending to these needs can take precedence over, and may be performed before, even mitzvot that must be done before one may eat or go to work, such as morning tefilla.[10] In fact, it is likely that the need to take care of children is at the very least partially behind the broad exemption of women from time-dependent mitzvot.[11] Taking care of the needs of one’s family justifies not pursuing mitzvot when the mitzva opportunity is one that is not clearly incumbent upon him (e.g., helping out someone in need when others have a closer connection or can do so more easily). We hopefully learn how to find the proper balance between family needs and mitzva opportunities from the example of our own parents.
Only if one has earned a deep relationship with his children can he expect success in inculcating them with a love of and a dedication to a Torah lifestyle. This approach to preparing the next generation has been the Jewish ideal since Avraham Avinu.[12] How the responsibilities of providing all of a child’s material, educational, and emotional needs are divided between two parents, sometimes with help from their families and the community, depends on the time, place, and the individuals’ circumstances.
We have demonstrated why taking care of one’s children, even if it were not a mitzva per se, would be a proper, central reality of life and should be done even when it limits or delays one’s ability to perform certain mitzvot. Now we will provide sources that indicate that taking care of one’s children is, in fact, a mitzva in its own right.
The gemara analyzes a pasuk[13] as follows: “‘Praiseworthy is one who guards justice, who does tzedaka every moment.’ Is it possible to do tzedaka every moment? Our rabbis in Yavneh said that it refers to one who supports his sons and daughters when they are young.”[14] Consider two difficulties in this gemara: 1) Why is supporting one’s own children considered tzedaka? (The gemara’s next opinion indeed interprets the pasuk as referring to raising orphans, which is easier to understand.) 2) How is supporting one’s children something that one can do at “every moment”? Rashi[15] answers both questions: 1) The gemara is talking about children who have reached an age at which there is no longer a full obligation to support them. The support of close family members takes tzedaka precedence over support of others, unless there is a halachic obligation to provide the support (e.g., a husband towards his wife), in which case it is not considered tzedaka.[16] 2) “Always, day and night, they are his responsibility.” I understand “day and night” as indicating that the responsibility in question is not only giving money, which one can do in a moment, but includes also the state of mind and reality that whatever and whenever needs arise, a mother or father will take care of them.
Elsewhere, the gemara[17] states that a father is exempt from the consequences of injuring his son while disciplining him, because such disciplining is a mitzva. It does not seem sensible that discipline is a mitzva whereas positive elements of child-rearing are not. This is thus another indication of a mitzva to raise children, this time from a more educational perspective.
Despite these sources about a mitzva to perform a variety of functions in child-rearing, one will not find this mitzva in any of the technical “lists of mitzvot,” as taking care of one’s children is not an independent mitzva. The Rambam[18] lists several acts of kindness as Rabbinic positive mitzvot, such as visiting the sick, comforting mourners, involvement in a funeral, and escorting a guest, among other acts. He concludes: “Although all of these mitzvot are of Rabbinic origin, they are included in ‘v’ahavta l’reiacha kamocha’ (You shall love your friend like yourself).”[19] This formulation is paradoxical. If a mitzva is of Rabbinic origin, it follows that it is not from the Torah. But if that is the case, then how can it be included in a mitzva of the Torah?! The Rambam apparently means the following. The Torah requires one to do his fair share of acts of kindness. However, an individual could fill his whole kindness quota by, say, visiting the sick, never taking part in funerals or bringing guests into his home. Therefore, the Rabbis instituted an independent obligation in each of the matters listed, in addition to the fact that they are already included in the general Torah mitzva of being kind and helpful to our counterparts.
Why are actions entailed in raising children not included in the above list of formal Rabbinic obligations?[20] It is possible that the list is not exhaustive. It is also possible that not only the Torah, but even the Rabbis in principle left these matters for a parent to do voluntarily (see above), even though practically, from a human perspective, they are activities that are incumbent upon the parent. Indeed, if one is unable (for various reasons) to do a lot of the caring for his children, he/she can arrange for others (e.g., pre-school, day care) to take a major part in providing the child’s physical, educational, and emotional needs. However, when a mother or father acts normally in raising his children, which includes a tremendous amount of work, this too is a fulfillment of “v’ahavta l’reiacha kamocha.”
Fundamentally, the above discussion applies equally to men and women. In practice, reason and practicality should guide a family on how to share and assign these responsibilities. It is uncommon, for example, for a father to have to miss putting on tefillin one day because he is too busy tending to his children. However, he might legitimately put them on later and miss minyan because a child is sick. A mother is more likely to spend a larger part of her day with her children, especially young ones, than a father does. Her crucial actions of child-rearing include both use of tremendous wisdom and sensitivity, on the one hand, as well as such mundane activities as cooking and changing diapers, on the other. But all contributions toward the child’s welfare, by both parents, are part of the general mitzva and a necessity we have tried to put in context.